diff --git a/compiler/rustc_abi/src/extern_abi/tests.rs b/compiler/rustc_abi/src/extern_abi/tests.rs
index fc546a6570f0a..8b9353ccae97b 100644
--- a/compiler/rustc_abi/src/extern_abi/tests.rs
+++ b/compiler/rustc_abi/src/extern_abi/tests.rs
@@ -1,6 +1,7 @@
-use std::assert_matches::assert_matches;
 use std::str::FromStr;
 
+use rustc_data_structures::assert_matches;
+
 use super::*;
 
 #[allow(non_snake_case)]
diff --git a/compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs b/compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs
index 834b1d988cb44..51792b7aff72c 100644
--- a/compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs
@@ -320,3 +320,27 @@ impl<S: Stage> NoArgsAttributeParser<S> for RustcHasIncoherentInherentImplsParse
     ]);
     const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcHasIncoherentInherentImpls;
 }
+
+pub(crate) struct RustcNounwindParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcNounwindParser {
+    const PATH: &[Symbol] = &[sym::rustc_nounwind];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[
+        Allow(Target::Fn),
+        Allow(Target::ForeignFn),
+        Allow(Target::Method(MethodKind::Inherent)),
+        Allow(Target::Method(MethodKind::TraitImpl)),
+        Allow(Target::Method(MethodKind::Trait { body: true })),
+    ]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcNounwind;
+}
+
+pub(crate) struct RustcOffloadKernelParser;
+
+impl<S: Stage> NoArgsAttributeParser<S> for RustcOffloadKernelParser {
+    const PATH: &[Symbol] = &[sym::rustc_offload_kernel];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const ALLOWED_TARGETS: AllowedTargets = AllowedTargets::AllowList(&[Allow(Target::Fn)]);
+    const CREATE: fn(Span) -> AttributeKind = |_| AttributeKind::RustcOffloadKernel;
+}
diff --git a/compiler/rustc_attr_parsing/src/context.rs b/compiler/rustc_attr_parsing/src/context.rs
index 1a06f4edeaa6d..0c882fee01c8a 100644
--- a/compiler/rustc_attr_parsing/src/context.rs
+++ b/compiler/rustc_attr_parsing/src/context.rs
@@ -78,8 +78,8 @@ use crate::attributes::rustc_internal::{
     RustcLintDiagnosticsParser, RustcLintOptDenyFieldAccessParser, RustcLintOptTyParser,
     RustcLintQueryInstabilityParser, RustcLintUntrackedQueryInformationParser, RustcMainParser,
     RustcMustImplementOneOfParser, RustcNeverReturnsNullPointerParser,
-    RustcNoImplicitAutorefsParser, RustcObjectLifetimeDefaultParser, RustcScalableVectorParser,
-    RustcSimdMonomorphizeLaneLimitParser,
+    RustcNoImplicitAutorefsParser, RustcNounwindParser, RustcObjectLifetimeDefaultParser,
+    RustcOffloadKernelParser, RustcScalableVectorParser, RustcSimdMonomorphizeLaneLimitParser,
 };
 use crate::attributes::semantics::MayDangleParser;
 use crate::attributes::stability::{
@@ -296,6 +296,8 @@ attribute_parsers!(
         Single<WithoutArgs<RustcMainParser>>,
         Single<WithoutArgs<RustcNeverReturnsNullPointerParser>>,
         Single<WithoutArgs<RustcNoImplicitAutorefsParser>>,
+        Single<WithoutArgs<RustcNounwindParser>>,
+        Single<WithoutArgs<RustcOffloadKernelParser>>,
         Single<WithoutArgs<RustcPassIndirectlyInNonRusticAbisParser>>,
         Single<WithoutArgs<RustcReallocatorParser>>,
         Single<WithoutArgs<RustcShouldNotBeCalledOnConstItems>>,
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index 743a28822eb97..8f643d8f460f2 100644
--- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
@@ -3,8 +3,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 
-use std::assert_matches::assert_matches;
-
+use rustc_data_structures::assert_matches;
 use rustc_errors::{Applicability, Diag, EmissionGuarantee};
 use rustc_hir as hir;
 use rustc_hir::intravisit::Visitor;
diff --git a/compiler/rustc_borrowck/src/type_check/input_output.rs b/compiler/rustc_borrowck/src/type_check/input_output.rs
index eb31b5de05d2d..f3b9dcc90a845 100644
--- a/compiler/rustc_borrowck/src/type_check/input_output.rs
+++ b/compiler/rustc_borrowck/src/type_check/input_output.rs
@@ -7,9 +7,8 @@
 //! `RETURN_PLACE` the MIR arguments) are always fully normalized (and
 //! contain revealed `impl Trait` values).
 
-use std::assert_matches::assert_matches;
-
 use itertools::Itertools;
+use rustc_data_structures::assert_matches;
 use rustc_hir as hir;
 use rustc_infer::infer::{BoundRegionConversionTime, RegionVariableOrigin};
 use rustc_middle::mir::*;
diff --git a/compiler/rustc_builtin_macros/src/test.rs b/compiler/rustc_builtin_macros/src/test.rs
index 6f14385d5d30d..d5f774865a9e1 100644
--- a/compiler/rustc_builtin_macros/src/test.rs
+++ b/compiler/rustc_builtin_macros/src/test.rs
@@ -1,12 +1,12 @@
 //! The expansion from a test function to the appropriate test struct for libtest
 //! Ideally, this code would be in libtest but for efficiency and error messages it lives here.
 
-use std::assert_matches::assert_matches;
 use std::iter;
 
 use rustc_ast::{self as ast, GenericParamKind, HasNodeId, attr, join_path_idents};
 use rustc_ast_pretty::pprust;
 use rustc_attr_parsing::AttributeParser;
+use rustc_data_structures::assert_matches;
 use rustc_errors::{Applicability, Diag, Level};
 use rustc_expand::base::*;
 use rustc_hir::Attribute;
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index ee1b6d45e149d..7f02518d6c0de 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -1,9 +1,8 @@
-use std::assert_matches::assert_matches;
-
 use rustc_abi::{BackendRepr, Float, Integer, Primitive, Scalar};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
 use rustc_codegen_ssa::mir::operand::OperandValue;
 use rustc_codegen_ssa::traits::*;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::ty::Instance;
 use rustc_middle::ty::layout::TyAndLayout;
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
index a728f3ea1e668..b27b1a88f1330 100644
--- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
+++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs
@@ -1,9 +1,9 @@
-use std::assert_matches::assert_matches;
 use std::sync::Arc;
 
 use itertools::Itertools;
 use rustc_abi::Align;
 use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods};
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::IndexVec;
 use rustc_middle::ty::TyCtxt;
diff --git a/compiler/rustc_codegen_llvm/src/intrinsic.rs b/compiler/rustc_codegen_llvm/src/intrinsic.rs
index c6aae89f1e51e..565db7d298bc9 100644
--- a/compiler/rustc_codegen_llvm/src/intrinsic.rs
+++ b/compiler/rustc_codegen_llvm/src/intrinsic.rs
@@ -1,4 +1,3 @@
-use std::assert_matches::assert_matches;
 use std::cmp::Ordering;
 use std::ffi::c_uint;
 use std::ptr;
@@ -13,6 +12,7 @@ use rustc_codegen_ssa::errors::{ExpectedPointerMutability, InvalidMonomorphizati
 use rustc_codegen_ssa::mir::operand::{OperandRef, OperandValue};
 use rustc_codegen_ssa::mir::place::{PlaceRef, PlaceValue};
 use rustc_codegen_ssa::traits::*;
+use rustc_data_structures::assert_matches;
 use rustc_hir::def_id::LOCAL_CRATE;
 use rustc_hir::{self as hir};
 use rustc_middle::mir::BinOp;
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 3e36bd8552b18..53121fc6275b8 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -1,4 +1,3 @@
-use std::assert_matches::assert_matches;
 use std::marker::PhantomData;
 use std::panic::AssertUnwindSafe;
 use std::path::{Path, PathBuf};
@@ -8,6 +7,7 @@ use std::{fs, io, mem, str, thread};
 
 use rustc_abi::Size;
 use rustc_ast::attr;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::jobserver::{self, Acquired};
 use rustc_data_structures::memmap::Mmap;
diff --git a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
index 1b0427e7e6766..e35d884b6711c 100644
--- a/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
+++ b/compiler/rustc_codegen_ssa/src/codegen_attrs.rs
@@ -347,6 +347,12 @@ fn process_builtin_attrs(
                 AttributeKind::RustcAllocatorZeroed => {
                     codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR_ZEROED
                 }
+                AttributeKind::RustcNounwind => {
+                    codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND
+                }
+                AttributeKind::RustcOffloadKernel => {
+                    codegen_fn_attrs.flags |= CodegenFnAttrFlags::OFFLOAD_KERNEL
+                }
                 _ => {}
             }
         }
@@ -356,14 +362,10 @@ fn process_builtin_attrs(
         };
 
         match name {
-            sym::rustc_nounwind => codegen_fn_attrs.flags |= CodegenFnAttrFlags::NEVER_UNWIND,
             sym::patchable_function_entry => {
                 codegen_fn_attrs.patchable_function_entry =
                     parse_patchable_function_entry(tcx, attr);
             }
-            sym::rustc_offload_kernel => {
-                codegen_fn_attrs.flags |= CodegenFnAttrFlags::OFFLOAD_KERNEL
-            }
             _ => {}
         }
     }
diff --git a/compiler/rustc_codegen_ssa/src/traits/builder.rs b/compiler/rustc_codegen_ssa/src/traits/builder.rs
index 4f45c614e0030..ba36188f05d15 100644
--- a/compiler/rustc_codegen_ssa/src/traits/builder.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/builder.rs
@@ -1,7 +1,7 @@
-use std::assert_matches::assert_matches;
 use std::ops::Deref;
 
 use rustc_abi::{Align, Scalar, Size, WrappingRange};
+use rustc_data_structures::assert_matches;
 use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrs;
 use rustc_middle::mir;
 use rustc_middle::ty::layout::{FnAbiOf, LayoutOf, TyAndLayout};
diff --git a/compiler/rustc_const_eval/src/check_consts/check.rs b/compiler/rustc_const_eval/src/check_consts/check.rs
index 3a85ca3760d20..95dbf42d4d441 100644
--- a/compiler/rustc_const_eval/src/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/check_consts/check.rs
@@ -1,11 +1,11 @@
 //! The `Visitor` responsible for actually checking a `mir::Body` for invalid operations.
 
-use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 use std::mem;
 use std::num::NonZero;
 use std::ops::Deref;
 
+use rustc_data_structures::assert_matches;
 use rustc_errors::{Diag, ErrorGuaranteed};
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
diff --git a/compiler/rustc_const_eval/src/interpret/call.rs b/compiler/rustc_const_eval/src/interpret/call.rs
index 94c6fd1b32387..9c8ca44c5e8f0 100644
--- a/compiler/rustc_const_eval/src/interpret/call.rs
+++ b/compiler/rustc_const_eval/src/interpret/call.rs
@@ -1,10 +1,10 @@
 //! Manages calling a concrete function (with known MIR body) with argument passing,
 //! and returning the return value to the caller.
-use std::assert_matches::assert_matches;
 use std::borrow::Cow;
 
 use either::{Left, Right};
 use rustc_abi::{self as abi, ExternAbi, FieldIdx, Integer, VariantIdx};
+use rustc_data_structures::assert_matches;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::layout::{IntegerExt, TyAndLayout};
 use rustc_middle::ty::{self, AdtDef, Instance, Ty, VariantDef};
diff --git a/compiler/rustc_const_eval/src/interpret/cast.rs b/compiler/rustc_const_eval/src/interpret/cast.rs
index 3485a5c625baa..43de2e7f078a8 100644
--- a/compiler/rustc_const_eval/src/interpret/cast.rs
+++ b/compiler/rustc_const_eval/src/interpret/cast.rs
@@ -1,8 +1,7 @@
-use std::assert_matches::assert_matches;
-
 use rustc_abi::{FieldIdx, Integer};
 use rustc_apfloat::ieee::{Double, Half, Quad, Single};
 use rustc_apfloat::{Float, FloatConvert};
+use rustc_data_structures::assert_matches;
 use rustc_middle::mir::CastKind;
 use rustc_middle::mir::interpret::{InterpResult, PointerArithmetic, Scalar};
 use rustc_middle::ty::adjustment::PointerCoercion;
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs
index d23369caffa42..aeadf0257ea8a 100644
--- a/compiler/rustc_const_eval/src/interpret/eval_context.rs
+++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs
@@ -1,7 +1,6 @@
-use std::assert_matches::debug_assert_matches;
-
 use either::{Left, Right};
 use rustc_abi::{Align, HasDataLayout, Size, TargetDataLayout};
+use rustc_data_structures::debug_assert_matches;
 use rustc_errors::DiagCtxtHandle;
 use rustc_hir::def_id::DefId;
 use rustc_hir::limit::Limit;
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics.rs b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
index fe1dd1b6eb352..e526f6120689a 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics.rs
@@ -4,10 +4,9 @@
 
 mod simd;
 
-use std::assert_matches::assert_matches;
-
 use rustc_abi::{FIRST_VARIANT, FieldIdx, HasDataLayout, Size, VariantIdx};
 use rustc_apfloat::ieee::{Double, Half, Quad, Single};
+use rustc_data_structures::assert_matches;
 use rustc_hir::def_id::CRATE_DEF_ID;
 use rustc_infer::infer::TyCtxtInferExt;
 use rustc_middle::mir::interpret::{CTFE_ALLOC_SALT, read_target_uint, write_target_uint};
diff --git a/compiler/rustc_const_eval/src/interpret/intrinsics/simd.rs b/compiler/rustc_const_eval/src/interpret/intrinsics/simd.rs
index 33a115384a88d..d7fe7801fb082 100644
--- a/compiler/rustc_const_eval/src/interpret/intrinsics/simd.rs
+++ b/compiler/rustc_const_eval/src/interpret/intrinsics/simd.rs
@@ -2,6 +2,7 @@ use either::Either;
 use rustc_abi::{BackendRepr, Endian};
 use rustc_apfloat::ieee::{Double, Half, Quad, Single};
 use rustc_apfloat::{Float, Round};
+use rustc_data_structures::assert_matches;
 use rustc_middle::mir::interpret::{InterpErrorKind, Pointer, UndefinedBehaviorInfo};
 use rustc_middle::ty::{FloatTy, ScalarInt, SimdAlign};
 use rustc_middle::{bug, err_ub_format, mir, span_bug, throw_unsup_format, ty};
@@ -10,7 +11,7 @@ use tracing::trace;
 
 use super::{
     ImmTy, InterpCx, InterpResult, Machine, MinMax, MulAddType, OpTy, PlaceTy, Provenance, Scalar,
-    Size, TyAndLayout, assert_matches, interp_ok, throw_ub_format,
+    Size, TyAndLayout, interp_ok, throw_ub_format,
 };
 use crate::interpret::Writeable;
 
diff --git a/compiler/rustc_const_eval/src/interpret/memory.rs b/compiler/rustc_const_eval/src/interpret/memory.rs
index 862fe47790808..a6c8b28cce9f4 100644
--- a/compiler/rustc_const_eval/src/interpret/memory.rs
+++ b/compiler/rustc_const_eval/src/interpret/memory.rs
@@ -6,7 +6,6 @@
 //! integer. It is crucial that these operations call `check_align` *before*
 //! short-circuiting the empty case!
 
-use std::assert_matches::assert_matches;
 use std::borrow::{Borrow, Cow};
 use std::cell::Cell;
 use std::collections::VecDeque;
@@ -14,6 +13,7 @@ use std::{fmt, ptr};
 
 use rustc_abi::{Align, HasDataLayout, Size};
 use rustc_ast::Mutability;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_middle::mir::display_allocation;
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};
diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs
index 9a956259ba57d..e8e77de8eb3e3 100644
--- a/compiler/rustc_const_eval/src/interpret/operand.rs
+++ b/compiler/rustc_const_eval/src/interpret/operand.rs
@@ -1,11 +1,10 @@
 //! Functions concerning immediate values and operands, and reading from operands.
 //! All high-level functions to read from memory work on operands as sources.
 
-use std::assert_matches::assert_matches;
-
 use either::{Either, Left, Right};
 use rustc_abi as abi;
 use rustc_abi::{BackendRepr, HasDataLayout, Size};
+use rustc_data_structures::assert_matches;
 use rustc_hir::def::Namespace;
 use rustc_middle::mir::interpret::ScalarSizeMismatch;
 use rustc_middle::ty::layout::{HasTyCtxt, HasTypingEnv, TyAndLayout};
diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs
index a409c7fad4175..d472c14253b55 100644
--- a/compiler/rustc_const_eval/src/interpret/place.rs
+++ b/compiler/rustc_const_eval/src/interpret/place.rs
@@ -2,10 +2,9 @@
 //! into a place.
 //! All high-level functions to write to memory work on places as destinations.
 
-use std::assert_matches::assert_matches;
-
 use either::{Either, Left, Right};
 use rustc_abi::{BackendRepr, HasDataLayout, Size};
+use rustc_data_structures::assert_matches;
 use rustc_middle::ty::Ty;
 use rustc_middle::ty::layout::TyAndLayout;
 use rustc_middle::{bug, mir, span_bug};
diff --git a/compiler/rustc_data_structures/src/graph/scc/mod.rs b/compiler/rustc_data_structures/src/graph/scc/mod.rs
index 1882e6e835a4e..91cbe3c533bbc 100644
--- a/compiler/rustc_data_structures/src/graph/scc/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/scc/mod.rs
@@ -8,7 +8,6 @@
 //! Typical examples would include: minimum element in SCC, maximum element
 //! reachable from it, etc.
 
-use std::assert_matches::debug_assert_matches;
 use std::fmt::Debug;
 use std::marker::PhantomData;
 use std::ops::Range;
@@ -16,6 +15,7 @@ use std::ops::Range;
 use rustc_index::{Idx, IndexSlice, IndexVec};
 use tracing::{debug, instrument, trace};
 
+use crate::debug_assert_matches;
 use crate::fx::FxHashSet;
 use crate::graph::vec_graph::VecGraph;
 use crate::graph::{DirectedGraph, NumEdges, Successors};
diff --git a/compiler/rustc_data_structures/src/lib.rs b/compiler/rustc_data_structures/src/lib.rs
index ff1dd41c82ccb..8377213850b86 100644
--- a/compiler/rustc_data_structures/src/lib.rs
+++ b/compiler/rustc_data_structures/src/lib.rs
@@ -38,6 +38,11 @@
 #![feature(unwrap_infallible)]
 // tidy-alphabetical-end
 
+// Temporarily re-export `assert_matches!`, so that the rest of the compiler doesn't
+// have to worry about it being moved to a different module in std during stabilization.
+// FIXME(#151359): Remove this when `feature(assert_matches)` is stable in stage0.
+// (This doesn't necessarily need to be fixed during the beta bump itself.)
+pub use std::assert_matches::{assert_matches, debug_assert_matches};
 use std::fmt;
 
 pub use atomic_ref::AtomicRef;
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 148368045f4f5..ce40f3ae8bf87 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -23,7 +23,6 @@
 
 extern crate self as rustc_errors;
 
-use std::assert_matches::assert_matches;
 use std::backtrace::{Backtrace, BacktraceStatus};
 use std::borrow::Cow;
 use std::cell::Cell;
@@ -55,10 +54,10 @@ pub use diagnostic_impls::{
 };
 pub use emitter::ColorConfig;
 use emitter::{ConfusionType, DynEmitter, Emitter, detect_confusion_type, is_different};
-use rustc_data_structures::AtomicRef;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_data_structures::sync::{DynSend, Lock};
+use rustc_data_structures::{AtomicRef, assert_matches};
 pub use rustc_error_messages::{
     DiagArg, DiagArgFromDisplay, DiagArgName, DiagArgValue, DiagMessage, FluentBundle, IntoDiagArg,
     LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagMessage,
diff --git a/compiler/rustc_hir/src/attrs/data_structures.rs b/compiler/rustc_hir/src/attrs/data_structures.rs
index 5cd508acc5676..314f36d6132d3 100644
--- a/compiler/rustc_hir/src/attrs/data_structures.rs
+++ b/compiler/rustc_hir/src/attrs/data_structures.rs
@@ -981,9 +981,15 @@ pub enum AttributeKind {
     /// Represents `#[rustc_no_implicit_autorefs]`
     RustcNoImplicitAutorefs,
 
+    /// Represents `#[rustc_nounwind]`
+    RustcNounwind,
+
     /// Represents `#[rustc_object_lifetime_default]`.
     RustcObjectLifetimeDefault,
 
+    /// Represents `#[rustc_offload_kernel]`
+    RustcOffloadKernel,
+
     /// Represents `#[rustc_pass_indirectly_in_non_rustic_abis]`
     RustcPassIndirectlyInNonRusticAbis(Span),
 
diff --git a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
index 19243c7d84683..b55a5d0e29e14 100644
--- a/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
+++ b/compiler/rustc_hir/src/attrs/encode_cross_crate.rs
@@ -122,7 +122,9 @@ impl AttributeKind {
             RustcMustImplementOneOf { .. } => No,
             RustcNeverReturnsNullPointer => Yes,
             RustcNoImplicitAutorefs => Yes,
+            RustcNounwind => No,
             RustcObjectLifetimeDefault => No,
+            RustcOffloadKernel => Yes,
             RustcPassIndirectlyInNonRusticAbis(..) => No,
             RustcReallocator => No,
             RustcScalableVector { .. } => Yes,
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index 2c02534093870..9c0b638c14828 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -14,13 +14,13 @@
 //! At present, however, we do run collection across all items in the
 //! crate as a kind of pass. This should eventually be factored away.
 
-use std::assert_matches::assert_matches;
 use std::cell::Cell;
 use std::iter;
 use std::ops::Bound;
 
 use rustc_abi::{ExternAbi, Size};
 use rustc_ast::Recovered;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_errors::{
     Applicability, Diag, DiagCtxtHandle, E0228, ErrorGuaranteed, StashKey, struct_span_code_err,
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 3d2f0466cad08..511d513216eb2 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -1,6 +1,6 @@
-use std::assert_matches::assert_matches;
 use std::ops::ControlFlow;
 
+use rustc_data_structures::assert_matches;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor, VisitorExt};
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 178c47b09c84d..a2236b4263059 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -1,6 +1,5 @@
-use std::assert_matches::assert_matches;
-
 use hir::Node;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
 use rustc_hir::attrs::AttributeKind;
diff --git a/compiler/rustc_hir_analysis/src/delegation.rs b/compiler/rustc_hir_analysis/src/delegation.rs
index cf0533c39e73f..f64341d755f8c 100644
--- a/compiler/rustc_hir_analysis/src/delegation.rs
+++ b/compiler/rustc_hir_analysis/src/delegation.rs
@@ -2,8 +2,7 @@
 //!
 //! For more information about delegation design, see the tracking issue #118212.
 
-use std::assert_matches::debug_assert_matches;
-
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::{DefId, LocalDefId};
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index 6e1e6c157a91e..924967b65c193 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -19,10 +19,10 @@ mod dyn_trait;
 pub mod errors;
 pub mod generics;
 
-use std::assert_matches::assert_matches;
 use std::slice;
 
 use rustc_ast::LitKind;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_errors::codes::*;
 use rustc_errors::{
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check.rs b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
index cadbc54c34108..f5c77c6800003 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check.rs
@@ -8,9 +8,8 @@
 //! specialization errors. These things can (and probably should) be
 //! fixed, but for the moment it's easier to do these checks early.
 
-use std::assert_matches::debug_assert_matches;
-
 use min_specialization::check_min_specialization;
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_errors::Applicability;
 use rustc_errors::codes::*;
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index beb0337d8c591..ed71ad2119c97 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -1,8 +1,8 @@
-use std::assert_matches::debug_assert_matches;
 use std::cell::{Cell, RefCell};
 use std::cmp::max;
 use std::ops::Deref;
 
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sso::SsoHashSet;
 use rustc_errors::Applicability;
diff --git a/compiler/rustc_infer/src/infer/outlives/verify.rs b/compiler/rustc_infer/src/infer/outlives/verify.rs
index f67b99cb3f846..affeb01e6d052 100644
--- a/compiler/rustc_infer/src/infer/outlives/verify.rs
+++ b/compiler/rustc_infer/src/infer/outlives/verify.rs
@@ -1,5 +1,4 @@
-use std::assert_matches::assert_matches;
-
+use rustc_data_structures::assert_matches;
 use rustc_middle::ty::outlives::{Component, compute_alias_components_recursive};
 use rustc_middle::ty::{self, OutlivesPredicate, Ty, TyCtxt};
 use smallvec::smallvec;
diff --git a/compiler/rustc_infer/src/infer/snapshot/undo_log.rs b/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
index c859d64133c49..a6f324b704716 100644
--- a/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
+++ b/compiler/rustc_infer/src/infer/snapshot/undo_log.rs
@@ -1,8 +1,7 @@
-use std::assert_matches::assert_matches;
 use std::marker::PhantomData;
 
 use rustc_data_structures::undo_log::{Rollback, UndoLogs};
-use rustc_data_structures::{snapshot_vec as sv, unify as ut};
+use rustc_data_structures::{assert_matches, snapshot_vec as sv, unify as ut};
 use rustc_middle::ty::{self, OpaqueTypeKey, ProvisionalHiddenType};
 use tracing::debug;
 
diff --git a/compiler/rustc_lint/src/impl_trait_overcaptures.rs b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
index 2fc9d562dc566..f6c2e5946079b 100644
--- a/compiler/rustc_lint/src/impl_trait_overcaptures.rs
+++ b/compiler/rustc_lint/src/impl_trait_overcaptures.rs
@@ -1,6 +1,6 @@
-use std::assert_matches::debug_assert_matches;
 use std::cell::LazyCell;
 
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
 use rustc_data_structures::unord::UnordSet;
 use rustc_errors::{LintDiagnostic, Subdiagnostic};
diff --git a/compiler/rustc_middle/src/ty/consts/kind.rs b/compiler/rustc_middle/src/ty/consts/kind.rs
index b3436550e8e07..c9ccb9bd0b3e9 100644
--- a/compiler/rustc_middle/src/ty/consts/kind.rs
+++ b/compiler/rustc_middle/src/ty/consts/kind.rs
@@ -1,5 +1,4 @@
-use std::assert_matches::assert_matches;
-
+use rustc_data_structures::assert_matches;
 use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
 
 use super::Const;
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index e9fa3f14358e8..a5aead9829f19 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -4,7 +4,6 @@
 
 pub mod tls;
 
-use std::assert_matches::debug_assert_matches;
 use std::borrow::{Borrow, Cow};
 use std::cmp::Ordering;
 use std::env::VarError;
@@ -17,7 +16,6 @@ use std::{fmt, iter, mem};
 
 use rustc_abi::{ExternAbi, FieldIdx, Layout, LayoutData, TargetDataLayout, VariantIdx};
 use rustc_ast as ast;
-use rustc_data_structures::defer;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::intern::Interned;
@@ -29,6 +27,7 @@ use rustc_data_structures::steal::Steal;
 use rustc_data_structures::sync::{
     self, DynSend, DynSync, FreezeReadGuard, Lock, RwLock, WorkerLocal,
 };
+use rustc_data_structures::{debug_assert_matches, defer};
 use rustc_errors::{
     Applicability, Diag, DiagCtxtHandle, ErrorGuaranteed, LintDiagnostic, MultiSpan,
 };
diff --git a/compiler/rustc_middle/src/ty/instance.rs b/compiler/rustc_middle/src/ty/instance.rs
index c27d47fcc0d8d..0e9dd7dd169cf 100644
--- a/compiler/rustc_middle/src/ty/instance.rs
+++ b/compiler/rustc_middle/src/ty/instance.rs
@@ -1,6 +1,6 @@
-use std::assert_matches::assert_matches;
 use std::fmt;
 
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 8eee114ead02e..ce713dcf42f54 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -11,7 +11,6 @@
 
 #![allow(rustc::usage_of_ty_tykind)]
 
-use std::assert_matches::assert_matches;
 use std::fmt::Debug;
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;
@@ -31,6 +30,7 @@ use rustc_ast::AttrVec;
 use rustc_ast::expand::typetree::{FncTree, Kind, Type, TypeTree};
 use rustc_ast::node_id::NodeMap;
 pub use rustc_ast_ir::{Movability, Mutability, try_visit};
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::intern::Interned;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index c282f2211f650..34aca8adb4a0d 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -2,12 +2,12 @@
 
 #![allow(rustc::usage_of_ty_tykind)]
 
-use std::assert_matches::debug_assert_matches;
 use std::borrow::Cow;
 use std::ops::{ControlFlow, Range};
 
 use hir::def::{CtorKind, DefKind};
 use rustc_abi::{FIRST_VARIANT, FieldIdx, ScalableElt, VariantIdx};
+use rustc_data_structures::debug_assert_matches;
 use rustc_errors::{ErrorGuaranteed, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::LangItem;
diff --git a/compiler/rustc_mir_build/src/builder/coverageinfo.rs b/compiler/rustc_mir_build/src/builder/coverageinfo.rs
index 091b9dad5bc15..ae36b2fb7f38c 100644
--- a/compiler/rustc_mir_build/src/builder/coverageinfo.rs
+++ b/compiler/rustc_mir_build/src/builder/coverageinfo.rs
@@ -1,6 +1,6 @@
-use std::assert_matches::assert_matches;
 use std::collections::hash_map::Entry;
 
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_middle::mir::coverage::{BlockMarkerId, BranchSpan, CoverageInfoHi, CoverageKind};
 use rustc_middle::mir::{self, BasicBlock, SourceInfo, UnOp};
diff --git a/compiler/rustc_mir_build/src/builder/expr/as_place.rs b/compiler/rustc_mir_build/src/builder/expr/as_place.rs
index 139c6da29d440..172dbf7c31b51 100644
--- a/compiler/rustc_mir_build/src/builder/expr/as_place.rs
+++ b/compiler/rustc_mir_build/src/builder/expr/as_place.rs
@@ -1,9 +1,9 @@
 //! See docs in build/expr/mod.rs
 
-use std::assert_matches::assert_matches;
 use std::iter;
 
 use rustc_abi::{FIRST_VARIANT, FieldIdx, VariantIdx};
+use rustc_data_structures::assert_matches;
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::hir::place::{Projection as HirProjection, ProjectionKind as HirProjectionKind};
 use rustc_middle::mir::AssertKind::BoundsCheck;
diff --git a/compiler/rustc_mir_build/src/builder/matches/mod.rs b/compiler/rustc_mir_build/src/builder/matches/mod.rs
index 11a181cfa8cea..2f9486c2d552e 100644
--- a/compiler/rustc_mir_build/src/builder/matches/mod.rs
+++ b/compiler/rustc_mir_build/src/builder/matches/mod.rs
@@ -5,13 +5,13 @@
 //! This also includes code for pattern bindings in `let` statements and
 //! function parameters.
 
-use std::assert_matches::debug_assert_matches;
 use std::borrow::Borrow;
 use std::mem;
 use std::sync::Arc;
 
 use itertools::{Itertools, Position};
 use rustc_abi::{FIRST_VARIANT, VariantIdx};
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir::{BindingMode, ByRef, LangItem, LetStmt, LocalSource, Node};
diff --git a/compiler/rustc_mir_build/src/builder/matches/user_ty.rs b/compiler/rustc_mir_build/src/builder/matches/user_ty.rs
index 2dcfd3772902c..6ba5e360ef828 100644
--- a/compiler/rustc_mir_build/src/builder/matches/user_ty.rs
+++ b/compiler/rustc_mir_build/src/builder/matches/user_ty.rs
@@ -4,10 +4,10 @@
 //! This avoids having to repeatedly clone a partly-built [`UserTypeProjections`]
 //! at every step of the traversal, which is what the previous code was doing.
 
-use std::assert_matches::assert_matches;
 use std::iter;
 
 use rustc_abi::{FieldIdx, VariantIdx};
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::smallvec::SmallVec;
 use rustc_middle::mir::{ProjectionElem, UserTypeProjection, UserTypeProjections};
 use rustc_middle::ty::{AdtDef, UserTypeAnnotationIndex};
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index 650650cbaac90..d0abb6396145d 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -4,11 +4,11 @@ mod check_match;
 mod const_to_pat;
 mod migration;
 
-use std::assert_matches::assert_matches;
 use std::cmp::Ordering;
 use std::sync::Arc;
 
 use rustc_abi::{FieldIdx, Integer};
+use rustc_data_structures::assert_matches;
 use rustc_errors::codes::*;
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::pat_util::EnumerateAndAdjustIterator;
diff --git a/compiler/rustc_mir_build/src/thir/util.rs b/compiler/rustc_mir_build/src/thir/util.rs
index 457957f5fce95..0093bb762110a 100644
--- a/compiler/rustc_mir_build/src/thir/util.rs
+++ b/compiler/rustc_mir_build/src/thir/util.rs
@@ -1,5 +1,4 @@
-use std::assert_matches::assert_matches;
-
+use rustc_data_structures::assert_matches;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_middle::bug;
diff --git a/compiler/rustc_mir_dataflow/src/impls/initialized.rs b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
index 9216106b6eddc..6a0881ec2bcb8 100644
--- a/compiler/rustc_mir_dataflow/src/impls/initialized.rs
+++ b/compiler/rustc_mir_dataflow/src/impls/initialized.rs
@@ -1,6 +1,5 @@
-use std::assert_matches::assert_matches;
-
 use rustc_abi::VariantIdx;
+use rustc_data_structures::assert_matches;
 use rustc_index::Idx;
 use rustc_index::bit_set::{DenseBitSet, MixedBitSet};
 use rustc_middle::bug;
diff --git a/compiler/rustc_mir_dataflow/src/value_analysis.rs b/compiler/rustc_mir_dataflow/src/value_analysis.rs
index ac94ee5c8104e..f102b7bb50f51 100644
--- a/compiler/rustc_mir_dataflow/src/value_analysis.rs
+++ b/compiler/rustc_mir_dataflow/src/value_analysis.rs
@@ -1,8 +1,8 @@
-use std::assert_matches::debug_assert_matches;
 use std::fmt::{Debug, Formatter};
 use std::ops::Range;
 
 use rustc_abi::{FieldIdx, VariantIdx};
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::{FxHashMap, FxIndexSet, StdEntry};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_index::IndexVec;
diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
index 5254f60a15036..604f1da1a3abb 100644
--- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
+++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs
@@ -2,7 +2,6 @@
 //!
 //! Currently, this pass only propagates scalar values.
 
-use std::assert_matches::assert_matches;
 use std::cell::RefCell;
 use std::fmt::Formatter;
 
@@ -11,6 +10,7 @@ use rustc_const_eval::const_eval::{DummyMachine, throw_machine_stop_str};
 use rustc_const_eval::interpret::{
     ImmTy, Immediate, InterpCx, OpTy, PlaceTy, Projectable, interp_ok,
 };
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def::DefKind;
 use rustc_middle::bug;
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
index 1e9665f4337d7..179ada36be754 100644
--- a/compiler/rustc_mir_transform/src/inline.rs
+++ b/compiler/rustc_mir_transform/src/inline.rs
@@ -1,10 +1,10 @@
 //! Inlining pass for MIR functions.
 
-use std::assert_matches::debug_assert_matches;
 use std::iter;
 use std::ops::{Range, RangeFrom};
 
 use rustc_abi::{ExternAbi, FieldIdx};
+use rustc_data_structures::debug_assert_matches;
 use rustc_hir::attrs::{InlineAttr, OptimizeAttr};
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefId;
diff --git a/compiler/rustc_mir_transform/src/promote_consts.rs b/compiler/rustc_mir_transform/src/promote_consts.rs
index 11266ccc2832a..2cc8e9d6739c8 100644
--- a/compiler/rustc_mir_transform/src/promote_consts.rs
+++ b/compiler/rustc_mir_transform/src/promote_consts.rs
@@ -10,12 +10,12 @@
 //! otherwise silence errors, if move analysis runs after promotion on broken
 //! MIR.
 
-use std::assert_matches::assert_matches;
 use std::cell::Cell;
 use std::{cmp, iter, mem};
 
 use either::{Left, Right};
 use rustc_const_eval::check_consts::{ConstCx, qualifs};
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_index::{IndexSlice, IndexVec};
diff --git a/compiler/rustc_mir_transform/src/shim.rs b/compiler/rustc_mir_transform/src/shim.rs
index 85e340c0a02ab..cc1cb3d4f3ff6 100644
--- a/compiler/rustc_mir_transform/src/shim.rs
+++ b/compiler/rustc_mir_transform/src/shim.rs
@@ -1,7 +1,7 @@
-use std::assert_matches::assert_matches;
 use std::{fmt, iter};
 
 use rustc_abi::{ExternAbi, FIRST_VARIANT, FieldIdx, VariantIdx};
+use rustc_data_structures::assert_matches;
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index d6e99bc540f74..c1ab8d76380ae 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -16,7 +16,6 @@ mod ty;
 pub mod asm;
 pub mod cfg_select;
 
-use std::assert_matches::debug_assert_matches;
 use std::{fmt, mem, slice};
 
 use attr_wrapper::{AttrWrapper, UsePreAttrPos};
@@ -40,6 +39,7 @@ use rustc_ast::{
     Mutability, Recovered, Safety, StrLit, Visibility, VisibilityKind,
 };
 use rustc_ast_pretty::pprust;
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::{Applicability, Diag, FatalError, MultiSpan, PResult};
 use rustc_index::interval::IntervalSet;
diff --git a/compiler/rustc_parse/src/parser/tests.rs b/compiler/rustc_parse/src/parser/tests.rs
index 62e97c0c308c1..2e1acca9e9af5 100644
--- a/compiler/rustc_parse/src/parser/tests.rs
+++ b/compiler/rustc_parse/src/parser/tests.rs
@@ -1,5 +1,4 @@
 #![allow(rustc::symbol_intern_string_literal)]
-use std::assert_matches::assert_matches;
 use std::io::prelude::*;
 use std::iter::Peekable;
 use std::path::PathBuf;
@@ -11,6 +10,7 @@ use rustc_ast::token::{self, Delimiter, Token};
 use rustc_ast::tokenstream::{DelimSpacing, DelimSpan, Spacing, TokenStream, TokenTree};
 use rustc_ast::{self as ast, PatKind, visit};
 use rustc_ast_pretty::pprust::item_to_string;
+use rustc_data_structures::assert_matches;
 use rustc_errors::annotate_snippet_emitter_writer::AnnotateSnippetEmitter;
 use rustc_errors::emitter::{HumanEmitter, OutputTheme};
 use rustc_errors::translation::Translator;
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 3a086ba5ff78e..8074ae4298923 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -322,6 +322,8 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     | AttributeKind::RustcAllocatorZeroedVariant { .. }
                     | AttributeKind::RustcDeallocator
                     | AttributeKind::RustcReallocator
+                    | AttributeKind::RustcNounwind
+                    | AttributeKind::RustcOffloadKernel
                 ) => { /* do nothing  */ }
                 Attribute::Unparsed(attr_item) => {
                     style = Some(attr_item.style);
@@ -390,7 +392,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                             | sym::rustc_partition_reused
                             | sym::rustc_partition_codegened
                             | sym::rustc_expected_cgu_reuse
-                            | sym::rustc_nounwind
                             // crate-level attrs, are checked below
                             | sym::feature
                             | sym::register_tool
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 0b50d376b5521..f32f3f78c04b2 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -1,4 +1,3 @@
-use std::assert_matches::assert_matches;
 use std::fmt::Debug;
 use std::hash::Hash;
 use std::marker::PhantomData;
@@ -7,12 +6,12 @@ use std::sync::atomic::{AtomicU32, Ordering};
 
 use rustc_data_structures::fingerprint::{Fingerprint, PackedFingerprint};
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
-use rustc_data_structures::outline;
 use rustc_data_structures::profiling::QueryInvocationId;
 use rustc_data_structures::sharded::{self, ShardedHashMap};
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_data_structures::sync::{AtomicU64, Lock};
 use rustc_data_structures::unord::UnordMap;
+use rustc_data_structures::{assert_matches, outline};
 use rustc_errors::DiagInner;
 use rustc_index::IndexVec;
 use rustc_macros::{Decodable, Encodable};
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 6557e1dea1a16..963bee369f6b8 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -6,7 +6,6 @@
 //! If you wonder why there's no `early.rs`, that's because it's split into three files -
 //! `build_reduced_graph.rs`, `macros.rs` and `imports.rs`.
 
-use std::assert_matches::debug_assert_matches;
 use std::borrow::Cow;
 use std::collections::hash_map::Entry;
 use std::mem::{replace, swap, take};
@@ -16,6 +15,7 @@ use rustc_ast::visit::{
     AssocCtxt, BoundKind, FnCtxt, FnKind, Visitor, try_visit, visit_opt, walk_list,
 };
 use rustc_ast::*;
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
 use rustc_data_structures::unord::{UnordMap, UnordSet};
 use rustc_errors::codes::*;
diff --git a/compiler/rustc_symbol_mangling/src/export.rs b/compiler/rustc_symbol_mangling/src/export.rs
index 3896e06a627b7..c99ba1d58f31f 100644
--- a/compiler/rustc_symbol_mangling/src/export.rs
+++ b/compiler/rustc_symbol_mangling/src/export.rs
@@ -1,6 +1,5 @@
-use std::assert_matches::debug_assert_matches;
-
 use rustc_abi::IntegerType;
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::stable_hasher::StableHasher;
 use rustc_hashes::Hash128;
 use rustc_hir::def::DefKind;
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index ef50dafec9503..1c08b5e331422 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -1,12 +1,12 @@
 // ignore-tidy-filelength
 
-use std::assert_matches::debug_assert_matches;
 use std::borrow::Cow;
 use std::iter;
 use std::path::PathBuf;
 
 use itertools::{EitherOrBoth, Itertools};
 use rustc_abi::ExternAbi;
+use rustc_data_structures::debug_assert_matches;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::codes::*;
diff --git a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
index 944d57bf95d12..ea8360c10b6fe 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect/analyse.rs
@@ -9,8 +9,7 @@
 //! coherence right now and was annoying to implement, so I am leaving it
 //! as is until we start using it for something else.
 
-use std::assert_matches::assert_matches;
-
+use rustc_data_structures::assert_matches;
 use rustc_infer::infer::InferCtxt;
 use rustc_infer::traits::Obligation;
 use rustc_macros::extension;
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index d6c9adfb28177..787dd4ea62549 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2,13 +2,13 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/resolution.html#selection
 
-use std::assert_matches::assert_matches;
 use std::cell::{Cell, RefCell};
 use std::cmp;
 use std::fmt::{self, Display};
 use std::ops::ControlFlow;
 
 use hir::def::DefKind;
+use rustc_data_structures::assert_matches;
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_errors::{Diag, EmissionGuarantee};
diff --git a/compiler/rustc_ty_utils/src/abi.rs b/compiler/rustc_ty_utils/src/abi.rs
index ad621c67772cc..34c080c4938f5 100644
--- a/compiler/rustc_ty_utils/src/abi.rs
+++ b/compiler/rustc_ty_utils/src/abi.rs
@@ -1,8 +1,8 @@
-use std::assert_matches::assert_matches;
 use std::iter;
 
 use rustc_abi::Primitive::Pointer;
 use rustc_abi::{BackendRepr, ExternAbi, PointerKind, Scalar, Size};
+use rustc_data_structures::assert_matches;
 use rustc_hir as hir;
 use rustc_hir::lang_items::LangItem;
 use rustc_middle::bug;
diff --git a/compiler/rustc_ty_utils/src/layout/invariant.rs b/compiler/rustc_ty_utils/src/layout/invariant.rs
index b013902f3fe3c..97c98d0c2403a 100644
--- a/compiler/rustc_ty_utils/src/layout/invariant.rs
+++ b/compiler/rustc_ty_utils/src/layout/invariant.rs
@@ -1,6 +1,5 @@
-use std::assert_matches::assert_matches;
-
 use rustc_abi::{BackendRepr, FieldsShape, Scalar, Size, TagEncoding, Variants};
+use rustc_data_structures::assert_matches;
 use rustc_middle::bug;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutCx, TyAndLayout};