diff --git a/compiler/rustc_ast_lowering/src/item.rs b/compiler/rustc_ast_lowering/src/item.rs
index edd0c5fb9647e..7b043705c1e0e 100644
--- a/compiler/rustc_ast_lowering/src/item.rs
+++ b/compiler/rustc_ast_lowering/src/item.rs
@@ -319,10 +319,10 @@ impl<'hir> LoweringContext<'_, 'hir> {
             },
             ItemKind::ForeignMod(ref fm) => {
                 if fm.abi.is_none() {
-                    self.maybe_lint_missing_abi(span, id, abi::Abi::C { unwind: false });
+                    self.maybe_lint_missing_abi(span, id, abi::Abi::C);
                 }
                 hir::ItemKind::ForeignMod {
-                    abi: fm.abi.map_or(abi::Abi::C { unwind: false }, |abi| self.lower_abi(abi)),
+                    abi: fm.abi.map_or(abi::Abi::C, |abi| self.lower_abi(abi)),
                     items: self
                         .arena
                         .alloc_from_iter(fm.items.iter().map(|x| self.lower_foreign_item_ref(x))),
@@ -1334,8 +1334,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         match ext {
             Extern::None => abi::Abi::Rust,
             Extern::Implicit => {
-                self.maybe_lint_missing_abi(span, id, abi::Abi::C { unwind: false });
-                abi::Abi::C { unwind: false }
+                self.maybe_lint_missing_abi(span, id, abi::Abi::C);
+                abi::Abi::C
             }
             Extern::Explicit(abi) => self.lower_abi(abi),
         }
diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
index 0ca9c12f4c133..1b79eafe36109 100644
--- a/compiler/rustc_ast_passes/src/feature_gate.rs
+++ b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -164,38 +164,6 @@ impl<'a> PostExpansionVisitor<'a> {
                     "C-cmse-nonsecure-call ABI is experimental and subject to change"
                 );
             }
-            "C-unwind" => {
-                gate_feature_post!(
-                    &self,
-                    c_unwind,
-                    span,
-                    "C-unwind ABI is experimental and subject to change"
-                );
-            }
-            "stdcall-unwind" => {
-                gate_feature_post!(
-                    &self,
-                    c_unwind,
-                    span,
-                    "stdcall-unwind ABI is experimental and subject to change"
-                );
-            }
-            "system-unwind" => {
-                gate_feature_post!(
-                    &self,
-                    c_unwind,
-                    span,
-                    "system-unwind ABI is experimental and subject to change"
-                );
-            }
-            "thiscall-unwind" => {
-                gate_feature_post!(
-                    &self,
-                    c_unwind,
-                    span,
-                    "thiscall-unwind ABI is experimental and subject to change"
-                );
-            }
             abi => self
                 .sess
                 .parse_sess
diff --git a/compiler/rustc_codegen_cranelift/src/abi/mod.rs b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
index b158d73f3a1a8..c79889f8ca1da 100644
--- a/compiler/rustc_codegen_cranelift/src/abi/mod.rs
+++ b/compiler/rustc_codegen_cranelift/src/abi/mod.rs
@@ -476,11 +476,8 @@ pub(crate) fn codegen_terminator_call<'tcx>(
 
     // FIXME find a cleaner way to support varargs
     if fn_sig.c_variadic {
-        if !matches!(fn_sig.abi, Abi::C { .. }) {
-            fx.tcx.sess.span_fatal(
-                span,
-                &format!("Variadic call for non-C abi {:?}", fn_sig.abi),
-            );
+        if fn_sig.abi != Abi::C {
+            fx.tcx.sess.span_fatal(span, &format!("Variadic call for non-C abi {:?}", fn_sig.abi));
         }
         let sig_ref = fx.bcx.func.dfg.call_signature(call_inst).unwrap();
         let abi_params = call_args
diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs
index 79ec9c264998c..a02117319cc13 100644
--- a/compiler/rustc_feature/src/active.rs
+++ b/compiler/rustc_feature/src/active.rs
@@ -644,9 +644,6 @@ declare_features! (
     /// Allows associated types in inherent impls.
     (active, inherent_associated_types, "1.52.0", Some(8995), None),
 
-    /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
-    (active, c_unwind, "1.52.0", Some(74990), None),
-
     // -------------------------------------------------------------------------
     // feature-group-end: actual feature gates
     // -------------------------------------------------------------------------
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index 2f5380861c495..6d2ab0e5f5a80 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -2654,14 +2654,14 @@ where
             RustIntrinsic | PlatformIntrinsic | Rust | RustCall => Conv::Rust,
 
             // It's the ABI's job to select this, not ours.
-            System { .. } => bug!("system abi should be selected elsewhere"),
+            System => bug!("system abi should be selected elsewhere"),
             EfiApi => bug!("eficall abi should be selected elsewhere"),
 
-            Stdcall { .. } => Conv::X86Stdcall,
+            Stdcall => Conv::X86Stdcall,
             Fastcall => Conv::X86Fastcall,
             Vectorcall => Conv::X86VectorCall,
-            Thiscall { .. } => Conv::X86ThisCall,
-            C { .. } => Conv::C,
+            Thiscall => Conv::X86ThisCall,
+            C => Conv::C,
             Unadjusted => Conv::C,
             Win64 => Conv::X86_64Win64,
             SysV64 => Conv::X86_64SysV,
diff --git a/compiler/rustc_mir/src/interpret/terminator.rs b/compiler/rustc_mir/src/interpret/terminator.rs
index 4aa1360d53539..0807949a2d91b 100644
--- a/compiler/rustc_mir/src/interpret/terminator.rs
+++ b/compiler/rustc_mir/src/interpret/terminator.rs
@@ -248,9 +248,9 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             };
             if normalize_abi(caller_abi) != normalize_abi(callee_abi) {
                 throw_ub_format!(
-                    "calling a function with ABI {} using caller ABI {}",
-                    callee_abi.name(),
-                    caller_abi.name()
+                    "calling a function with ABI {:?} using caller ABI {:?}",
+                    callee_abi,
+                    caller_abi
                 )
             }
         }
diff --git a/compiler/rustc_span/src/symbol.rs b/compiler/rustc_span/src/symbol.rs
index cd3dabb67950b..5aa6275a96166 100644
--- a/compiler/rustc_span/src/symbol.rs
+++ b/compiler/rustc_span/src/symbol.rs
@@ -330,7 +330,6 @@ symbols! {
         bridge,
         bswap,
         c_str,
-        c_unwind,
         c_variadic,
         call,
         call_mut,
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index 12c0a147990fa..bbf7ecc39cfd9 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -440,7 +440,7 @@ impl Printer<'tcx> for SymbolMangler<'tcx> {
                     }
                     match sig.abi {
                         Abi::Rust => {}
-                        Abi::C { unwind: false } => cx.push("KC"),
+                        Abi::C => cx.push("KC"),
                         abi => {
                             cx.push("K");
                             let name = abi.name();
diff --git a/compiler/rustc_target/src/spec/abi.rs b/compiler/rustc_target/src/spec/abi.rs
index f7f9c30d3b7a6..65e8a4e8db2ad 100644
--- a/compiler/rustc_target/src/spec/abi.rs
+++ b/compiler/rustc_target/src/spec/abi.rs
@@ -8,21 +8,24 @@ mod tests;
 #[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy, Debug)]
 #[derive(HashStable_Generic, Encodable, Decodable)]
 pub enum Abi {
+    // N.B., this ordering MUST match the AbiDatas array below.
+    // (This is ensured by the test indices_are_correct().)
+
     // Multiplatform / generic ABIs
     //
     // These ABIs come first because every time we add a new ABI, we
     // have to re-bless all the hashing tests. These are used in many
     // places, so giving them stable values reduces test churn. The
     // specific values are meaningless.
-    Rust,
-    C { unwind: bool },
+    Rust = 0,
+    C = 1,
 
     // Single platform ABIs
     Cdecl,
-    Stdcall { unwind: bool },
+    Stdcall,
     Fastcall,
     Vectorcall,
-    Thiscall { unwind: bool },
+    Thiscall,
     Aapcs,
     Win64,
     SysV64,
@@ -36,7 +39,7 @@ pub enum Abi {
     CCmseNonSecureCall,
 
     // Multiplatform / generic ABIs
-    System { unwind: bool },
+    System,
     RustIntrinsic,
     RustCall,
     PlatformIntrinsic,
@@ -58,16 +61,13 @@ pub struct AbiData {
 const AbiDatas: &[AbiData] = &[
     // Cross-platform ABIs
     AbiData { abi: Abi::Rust, name: "Rust", generic: true },
-    AbiData { abi: Abi::C { unwind: false }, name: "C", generic: true },
-    AbiData { abi: Abi::C { unwind: true }, name: "C-unwind", generic: true },
+    AbiData { abi: Abi::C, name: "C", generic: true },
     // Platform-specific ABIs
     AbiData { abi: Abi::Cdecl, name: "cdecl", generic: false },
-    AbiData { abi: Abi::Stdcall { unwind: false }, name: "stdcall", generic: false },
-    AbiData { abi: Abi::Stdcall { unwind: true }, name: "stdcall-unwind", generic: false },
+    AbiData { abi: Abi::Stdcall, name: "stdcall", generic: false },
     AbiData { abi: Abi::Fastcall, name: "fastcall", generic: false },
     AbiData { abi: Abi::Vectorcall, name: "vectorcall", generic: false },
-    AbiData { abi: Abi::Thiscall { unwind: false }, name: "thiscall", generic: false },
-    AbiData { abi: Abi::Thiscall { unwind: true }, name: "thiscall-unwind", generic: false },
+    AbiData { abi: Abi::Thiscall, name: "thiscall", generic: false },
     AbiData { abi: Abi::Aapcs, name: "aapcs", generic: false },
     AbiData { abi: Abi::Win64, name: "win64", generic: false },
     AbiData { abi: Abi::SysV64, name: "sysv64", generic: false },
@@ -84,8 +84,7 @@ const AbiDatas: &[AbiData] = &[
     },
     AbiData { abi: Abi::CCmseNonSecureCall, name: "C-cmse-nonsecure-call", generic: false },
     // Cross-platform ABIs
-    AbiData { abi: Abi::System { unwind: false }, name: "system", generic: true },
-    AbiData { abi: Abi::System { unwind: true }, name: "system-unwind", generic: true },
+    AbiData { abi: Abi::System, name: "system", generic: true },
     AbiData { abi: Abi::RustIntrinsic, name: "rust-intrinsic", generic: true },
     AbiData { abi: Abi::RustCall, name: "rust-call", generic: true },
     AbiData { abi: Abi::PlatformIntrinsic, name: "platform-intrinsic", generic: true },
@@ -104,41 +103,7 @@ pub fn all_names() -> Vec<&'static str> {
 impl Abi {
     #[inline]
     pub fn index(self) -> usize {
-        // N.B., this ordering MUST match the AbiDatas array above.
-        // (This is ensured by the test indices_are_correct().)
-        use Abi::*;
-        match self {
-            // Cross-platform ABIs
-            Rust => 0,
-            C { unwind: false } => 1,
-            C { unwind: true } => 2,
-            // Platform-specific ABIs
-            Cdecl => 3,
-            Stdcall { unwind: false } => 4,
-            Stdcall { unwind: true } => 5,
-            Fastcall => 6,
-            Vectorcall => 7,
-            Thiscall { unwind: false } => 8,
-            Thiscall { unwind: true } => 9,
-            Aapcs => 10,
-            Win64 => 11,
-            SysV64 => 12,
-            PtxKernel => 13,
-            Msp430Interrupt => 14,
-            X86Interrupt => 15,
-            AmdGpuKernel => 16,
-            EfiApi => 17,
-            AvrInterrupt => 18,
-            AvrNonBlockingInterrupt => 19,
-            CCmseNonSecureCall => 20,
-            // Cross-platform ABIs
-            System { unwind: false } => 21,
-            System { unwind: true } => 22,
-            RustIntrinsic => 23,
-            RustCall => 24,
-            PlatformIntrinsic => 25,
-            Unadjusted => 26,
-        }
+        self as usize
     }
 
     #[inline]
@@ -157,8 +122,6 @@ impl Abi {
 
 impl fmt::Display for Abi {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        match self {
-            abi => write!(f, "\"{}\"", abi.name()),
-        }
+        write!(f, "\"{}\"", self.name())
     }
 }
diff --git a/compiler/rustc_target/src/spec/arm_base.rs b/compiler/rustc_target/src/spec/arm_base.rs
index 01f573313c97f..b74d80dc6bb2b 100644
--- a/compiler/rustc_target/src/spec/arm_base.rs
+++ b/compiler/rustc_target/src/spec/arm_base.rs
@@ -2,14 +2,5 @@ use crate::spec::abi::Abi;
 
 // All the calling conventions trigger an assertion(Unsupported calling convention) in llvm on arm
 pub fn unsupported_abis() -> Vec<Abi> {
-    vec![
-        Abi::Stdcall { unwind: false },
-        Abi::Stdcall { unwind: true },
-        Abi::Fastcall,
-        Abi::Vectorcall,
-        Abi::Thiscall { unwind: false },
-        Abi::Thiscall { unwind: true },
-        Abi::Win64,
-        Abi::SysV64,
-    ]
+    vec![Abi::Stdcall, Abi::Fastcall, Abi::Vectorcall, Abi::Thiscall, Abi::Win64, Abi::SysV64]
 }
diff --git a/compiler/rustc_target/src/spec/mipsel_unknown_none.rs b/compiler/rustc_target/src/spec/mipsel_unknown_none.rs
index 110c8dd80ea77..0f9d3c3de1543 100644
--- a/compiler/rustc_target/src/spec/mipsel_unknown_none.rs
+++ b/compiler/rustc_target/src/spec/mipsel_unknown_none.rs
@@ -23,12 +23,10 @@ pub fn target() -> Target {
             panic_strategy: PanicStrategy::Abort,
             relocation_model: RelocModel::Static,
             unsupported_abis: vec![
-                Abi::Stdcall { unwind: false },
-                Abi::Stdcall { unwind: true },
+                Abi::Stdcall,
                 Abi::Fastcall,
                 Abi::Vectorcall,
-                Abi::Thiscall { unwind: false },
-                Abi::Thiscall { unwind: true },
+                Abi::Thiscall,
                 Abi::Win64,
                 Abi::SysV64,
             ],
diff --git a/compiler/rustc_target/src/spec/mod.rs b/compiler/rustc_target/src/spec/mod.rs
index c9fffd213d768..09400a1d13066 100644
--- a/compiler/rustc_target/src/spec/mod.rs
+++ b/compiler/rustc_target/src/spec/mod.rs
@@ -1284,31 +1284,24 @@ impl Target {
     /// Given a function ABI, turn it into the correct ABI for this target.
     pub fn adjust_abi(&self, abi: Abi) -> Abi {
         match abi {
-            Abi::System { unwind } => {
+            Abi::System => {
                 if self.is_like_windows && self.arch == "x86" {
-                    Abi::Stdcall { unwind }
+                    Abi::Stdcall
                 } else {
-                    Abi::C { unwind }
+                    Abi::C
                 }
             }
             // These ABI kinds are ignored on non-x86 Windows targets.
             // See https://docs.microsoft.com/en-us/cpp/cpp/argument-passing-and-naming-conventions
             // and the individual pages for __stdcall et al.
-            Abi::Stdcall { unwind } | Abi::Thiscall { unwind } => {
-                if self.is_like_windows && self.arch != "x86" { Abi::C { unwind } } else { abi }
-            }
-            Abi::Fastcall | Abi::Vectorcall => {
-                if self.is_like_windows && self.arch != "x86" {
-                    Abi::C { unwind: false }
-                } else {
-                    abi
-                }
+            Abi::Stdcall | Abi::Fastcall | Abi::Vectorcall | Abi::Thiscall => {
+                if self.is_like_windows && self.arch != "x86" { Abi::C } else { abi }
             }
             Abi::EfiApi => {
                 if self.arch == "x86_64" {
                     Abi::Win64
                 } else {
-                    Abi::C { unwind: false }
+                    Abi::C
                 }
             }
             abi => abi,
diff --git a/compiler/rustc_target/src/spec/nvptx64_nvidia_cuda.rs b/compiler/rustc_target/src/spec/nvptx64_nvidia_cuda.rs
index 15d8e4843f976..3c9c7d578fbd4 100644
--- a/compiler/rustc_target/src/spec/nvptx64_nvidia_cuda.rs
+++ b/compiler/rustc_target/src/spec/nvptx64_nvidia_cuda.rs
@@ -49,12 +49,10 @@ pub fn target() -> Target {
             // create the tests for this.
             unsupported_abis: vec![
                 Abi::Cdecl,
-                Abi::Stdcall { unwind: false },
-                Abi::Stdcall { unwind: true },
+                Abi::Stdcall,
                 Abi::Fastcall,
                 Abi::Vectorcall,
-                Abi::Thiscall { unwind: false },
-                Abi::Thiscall { unwind: true },
+                Abi::Thiscall,
                 Abi::Aapcs,
                 Abi::Win64,
                 Abi::SysV64,
diff --git a/compiler/rustc_target/src/spec/riscv_base.rs b/compiler/rustc_target/src/spec/riscv_base.rs
index 5bcbb2e621bd0..64cf890037e51 100644
--- a/compiler/rustc_target/src/spec/riscv_base.rs
+++ b/compiler/rustc_target/src/spec/riscv_base.rs
@@ -5,12 +5,10 @@ use crate::spec::abi::Abi;
 pub fn unsupported_abis() -> Vec<Abi> {
     vec![
         Abi::Cdecl,
-        Abi::Stdcall { unwind: false },
-        Abi::Stdcall { unwind: true },
+        Abi::Stdcall,
         Abi::Fastcall,
         Abi::Vectorcall,
-        Abi::Thiscall { unwind: false },
-        Abi::Thiscall { unwind: true },
+        Abi::Thiscall,
         Abi::Aapcs,
         Abi::Win64,
         Abi::SysV64,
diff --git a/compiler/rustc_typeck/src/collect.rs b/compiler/rustc_typeck/src/collect.rs
index e5136355ca982..b445143415795 100644
--- a/compiler/rustc_typeck/src/collect.rs
+++ b/compiler/rustc_typeck/src/collect.rs
@@ -2678,7 +2678,7 @@ fn codegen_fn_attrs(tcx: TyCtxt<'_>, id: DefId) -> CodegenFnAttrs {
         } else if tcx.sess.check_name(attr, sym::used) {
             codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED;
         } else if tcx.sess.check_name(attr, sym::cmse_nonsecure_entry) {
-            if !matches!(tcx.fn_sig(id).abi(), abi::Abi::C { .. }) {
+            if tcx.fn_sig(id).abi() != abi::Abi::C {
                 struct_span_err!(
                     tcx.sess,
                     attr.span,
diff --git a/compiler/rustc_typeck/src/lib.rs b/compiler/rustc_typeck/src/lib.rs
index 88b47bf5b9cdd..c8597408b51b3 100644
--- a/compiler/rustc_typeck/src/lib.rs
+++ b/compiler/rustc_typeck/src/lib.rs
@@ -118,19 +118,14 @@ use astconv::AstConv;
 use bounds::Bounds;
 
 fn require_c_abi_if_c_variadic(tcx: TyCtxt<'_>, decl: &hir::FnDecl<'_>, abi: Abi, span: Span) {
-    match (decl.c_variadic, abi) {
-        // The function has the correct calling convention, or isn't a "C-variadic" function.
-        (false, _) | (true, Abi::C { .. }) | (true, Abi::Cdecl) => {}
-        // The function is a "C-variadic" function with an incorrect calling convention.
-        (true, _) => {
-            let mut err = struct_span_err!(
-                tcx.sess,
-                span,
-                E0045,
-                "C-variadic function must have C or cdecl calling convention"
-            );
-            err.span_label(span, "C-variadics require C or cdecl calling convention").emit();
-        }
+    if decl.c_variadic && !(abi == Abi::C || abi == Abi::Cdecl) {
+        let mut err = struct_span_err!(
+            tcx.sess,
+            span,
+            E0045,
+            "C-variadic function must have C or cdecl calling convention"
+        );
+        err.span_label(span, "C-variadics require C or cdecl calling convention").emit();
     }
 }
 
diff --git a/src/doc/unstable-book/src/language-features/c-unwind.md b/src/doc/unstable-book/src/language-features/c-unwind.md
deleted file mode 100644
index c1705d59acc21..0000000000000
--- a/src/doc/unstable-book/src/language-features/c-unwind.md
+++ /dev/null
@@ -1,14 +0,0 @@
-# `c_unwind`
-
-The tracking issue for this feature is: [#74990]
-
-[#74990]: https://github.com/rust-lang/rust/issues/74990
-
-------------------------
-
-Introduces a new ABI string, "C-unwind", to enable unwinding from other
-languages (such as C++) into Rust frames and from Rust into other languages.
-
-See [RFC 2945] for more information.
-
-[RFC 2945]: https://github.com/rust-lang/rfcs/blob/master/text/2945-c-unwind-abi.md
diff --git a/src/test/ui/codemap_tests/unicode.stderr b/src/test/ui/codemap_tests/unicode.stderr
index b7ba4fa46d92b..61c3f4f1c9847 100644
--- a/src/test/ui/codemap_tests/unicode.stderr
+++ b/src/test/ui/codemap_tests/unicode.stderr
@@ -4,7 +4,7 @@ error[E0703]: invalid ABI: found `路濫狼á́́`
 LL | extern "路濫狼á́́" fn foo() {}
    |        ^^^^^^^^^ invalid ABI
    |
-   = help: valid ABIs: Rust, C, C-unwind, cdecl, stdcall, stdcall-unwind, fastcall, vectorcall, thiscall, thiscall-unwind, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, avr-interrupt, avr-non-blocking-interrupt, C-cmse-nonsecure-call, system, system-unwind, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
+   = help: valid ABIs: Rust, C, cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, avr-interrupt, avr-non-blocking-interrupt, C-cmse-nonsecure-call, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/parser/issue-8537.stderr b/src/test/ui/parser/issue-8537.stderr
index 85e2b77d867b9..3f63c08021098 100644
--- a/src/test/ui/parser/issue-8537.stderr
+++ b/src/test/ui/parser/issue-8537.stderr
@@ -4,7 +4,7 @@ error[E0703]: invalid ABI: found `invalid-ab_isize`
 LL |   "invalid-ab_isize"
    |   ^^^^^^^^^^^^^^^^^^ invalid ABI
    |
-   = help: valid ABIs: Rust, C, C-unwind, cdecl, stdcall, stdcall-unwind, fastcall, vectorcall, thiscall, thiscall-unwind, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, avr-interrupt, avr-non-blocking-interrupt, C-cmse-nonsecure-call, system, system-unwind, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
+   = help: valid ABIs: Rust, C, cdecl, stdcall, fastcall, vectorcall, thiscall, aapcs, win64, sysv64, ptx-kernel, msp430-interrupt, x86-interrupt, amdgpu-kernel, efiapi, avr-interrupt, avr-non-blocking-interrupt, C-cmse-nonsecure-call, system, rust-intrinsic, rust-call, platform-intrinsic, unadjusted
 
 error: aborting due to previous error
 
diff --git a/src/test/ui/symbol-names/impl1.rs b/src/test/ui/symbol-names/impl1.rs
index d3f74c4a4b7b0..771695330d8bd 100644
--- a/src/test/ui/symbol-names/impl1.rs
+++ b/src/test/ui/symbol-names/impl1.rs
@@ -74,7 +74,3 @@ fn main() {
         }
     };
 }
-
-// FIXME(katie): The 32-bit symbol hash probably needs updating as well, but I'm slightly unsure
-// about how to do that. This comment is here so that we don't break the test due to error messages
-// including incorrect line numbers.
diff --git a/src/test/ui/unwind-abis/feature-gate-c-unwind-enabled.rs b/src/test/ui/unwind-abis/feature-gate-c-unwind-enabled.rs
deleted file mode 100644
index 6ff5dbda2d560..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-c-unwind-enabled.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-// Test that the "C-unwind" ABI is feature-gated, and *can* be used when the
-// `c_unwind` feature gate is enabled.
-
-// check-pass
-
-#![feature(c_unwind)]
-
-extern "C-unwind" fn f() {}
-
-fn main() {
-    f();
-}
diff --git a/src/test/ui/unwind-abis/feature-gate-c-unwind.rs b/src/test/ui/unwind-abis/feature-gate-c-unwind.rs
deleted file mode 100644
index f02a368d4e097..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-c-unwind.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-// Test that the "C-unwind" ABI is feature-gated, and cannot be used when the
-// `c_unwind` feature gate is not used.
-
-extern "C-unwind" fn f() {}
-//~^ ERROR C-unwind ABI is experimental and subject to change [E0658]
-
-fn main() {
-    f();
-}
diff --git a/src/test/ui/unwind-abis/feature-gate-c-unwind.stderr b/src/test/ui/unwind-abis/feature-gate-c-unwind.stderr
deleted file mode 100644
index f4c785a235f67..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-c-unwind.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0658]: C-unwind ABI is experimental and subject to change
-  --> $DIR/feature-gate-c-unwind.rs:4:8
-   |
-LL | extern "C-unwind" fn f() {}
-   |        ^^^^^^^^^^
-   |
-   = note: see issue #74990 <https://github.com/rust-lang/rust/issues/74990> for more information
-   = help: add `#![feature(c_unwind)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.rs b/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.rs
deleted file mode 100644
index 7d4dc8c9343f1..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// ignore-arm stdcall isn't supported
-// ignore-aarch64 stdcall isn't supported
-// ignore-riscv64 stdcall isn't supported
-
-// Test that the "stdcall-unwind" ABI is feature-gated, and cannot be used when
-// the `c_unwind` feature gate is not used.
-
-extern "stdcall-unwind" fn f() {}
-//~^ ERROR stdcall-unwind ABI is experimental and subject to change [E0658]
-
-fn main() {
-    f();
-}
diff --git a/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.stderr b/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.stderr
deleted file mode 100644
index e3d569f464f87..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-stdcall-unwind.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0658]: stdcall-unwind ABI is experimental and subject to change
-  --> $DIR/feature-gate-stdcall-unwind.rs:8:8
-   |
-LL | extern "stdcall-unwind" fn f() {}
-   |        ^^^^^^^^^^^^^^^^
-   |
-   = note: see issue #74990 <https://github.com/rust-lang/rust/issues/74990> for more information
-   = help: add `#![feature(c_unwind)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/unwind-abis/feature-gate-system-unwind.rs b/src/test/ui/unwind-abis/feature-gate-system-unwind.rs
deleted file mode 100644
index 26c2de4e81767..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-system-unwind.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-// Test that the "system-unwind" ABI is feature-gated, and cannot be used when
-// the `c_unwind` feature gate is not used.
-
-extern "system-unwind" fn f() {}
-//~^ ERROR system-unwind ABI is experimental and subject to change [E0658]
-
-fn main() {
-    f();
-}
diff --git a/src/test/ui/unwind-abis/feature-gate-system-unwind.stderr b/src/test/ui/unwind-abis/feature-gate-system-unwind.stderr
deleted file mode 100644
index 87877336475b4..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-system-unwind.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0658]: system-unwind ABI is experimental and subject to change
-  --> $DIR/feature-gate-system-unwind.rs:4:8
-   |
-LL | extern "system-unwind" fn f() {}
-   |        ^^^^^^^^^^^^^^^
-   |
-   = note: see issue #74990 <https://github.com/rust-lang/rust/issues/74990> for more information
-   = help: add `#![feature(c_unwind)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.rs b/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.rs
deleted file mode 100644
index 2f4cefccc1967..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// ignore-arm thiscall isn't supported
-// ignore-aarch64 thiscall isn't supported
-// ignore-riscv64 thiscall isn't supported
-
-// Test that the "thiscall-unwind" ABI is feature-gated, and cannot be used when
-// the `c_unwind` feature gate is not used.
-
-extern "thiscall-unwind" fn f() {}
-//~^ ERROR thiscall-unwind ABI is experimental and subject to change [E0658]
-
-fn main() {
-    f();
-}
diff --git a/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.stderr b/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.stderr
deleted file mode 100644
index b103bb8d56585..0000000000000
--- a/src/test/ui/unwind-abis/feature-gate-thiscall-unwind.stderr
+++ /dev/null
@@ -1,12 +0,0 @@
-error[E0658]: thiscall-unwind ABI is experimental and subject to change
-  --> $DIR/feature-gate-thiscall-unwind.rs:8:8
-   |
-LL | extern "thiscall-unwind" fn f() {}
-   |        ^^^^^^^^^^^^^^^^^
-   |
-   = note: see issue #74990 <https://github.com/rust-lang/rust/issues/74990> for more information
-   = help: add `#![feature(c_unwind)]` to the crate attributes to enable
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0658`.