Revert "Use workspace lints for crates in compiler/ rust-lang#138084"

Revert <rust-lang#138084> to buy time to
consider options that avoids breaking downstream usages of cargo on
distributed `rustc-src` artifacts, where such cargo invocations fail due
to inability to inherit `lints` from workspace root manifest's
`workspace.lints` (this is only valid for the source rust-lang/rust
workspace, but not really the distributed `rustc-src` artifacts).

This breakage was reported in
<rust-lang#138304>.

This reverts commit 48caf81, reversing
changes made to c666287.

Author: jieyouxu

Cargo.toml

@@ -63,20 +63,6 @@ exclude = [
   "src/tools/x",
 ]
 
-# These lints are applied to many crates in the workspace. In practice, this is
-# all crates under `compiler/`.
-#
-# NOTE: rustc-specific lints (e.g. `rustc::internal`) aren't supported by
-# Cargo. (Support for them is possibly blocked by #44690 (attributes for
-# tools).) Those lints are instead specified for `compiler/` crates in
-# `src/bootstrap/src/core/builder/cargo.rs`.
-[workspace.lints.rust]
-# FIXME(edition_2024): Change this to `-Wrust_2024_idioms` when all of the
-# individual lints are satisfied.
-keyword_idents_2024 = "warn"
-unreachable_pub = "warn"
-unsafe_op_in_unsafe_fn = "warn"
-
 [profile.release.package.rustc-rayon-core]
 # The rustc fork of Rayon has deadlock detection code which intermittently
 # causes overflows in the CI (see https://github.com/rust-lang/rust/issues/90227)

compiler/rustc/Cargo.toml

@@ -32,6 +32,3 @@ llvm = ['rustc_driver_impl/llvm']
 max_level_info = ['rustc_driver_impl/max_level_info']
 rustc_randomized_layouts = ['rustc_driver_impl/rustc_randomized_layouts']
 # tidy-alphabetical-end
-
-[lints]
-workspace = true

compiler/rustc_abi/Cargo.toml

@@ -31,6 +31,3 @@ nightly = [
 ]
 randomize = ["dep:rand", "dep:rand_xoshiro", "nightly"]
 # tidy-alphabetical-end
-
-[lints]
-workspace = true

compiler/rustc_abi/src/lib.rs

@@ -5,6 +5,7 @@
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
 #![cfg_attr(feature = "nightly", feature(rustdoc_internals))]
 #![cfg_attr(feature = "nightly", feature(step_trait))]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 /*! ABI handling for rustc

compiler/rustc_arena/Cargo.toml

@@ -7,6 +7,3 @@ edition = "2024"
 # tidy-alphabetical-start
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 # tidy-alphabetical-end
-
-[lints]
-workspace = true

compiler/rustc_arena/src/lib.rs

@@ -23,6 +23,7 @@
 #![feature(maybe_uninit_slice)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 use std::alloc::Layout;

compiler/rustc_ast/Cargo.toml

@@ -18,6 +18,3 @@ smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.12"
 tracing = "0.1"
 # tidy-alphabetical-end
-
-[lints]
-workspace = true

compiler/rustc_ast/src/lib.rs

@@ -19,6 +19,7 @@
 #![feature(never_type)]
 #![feature(rustdoc_internals)]
 #![feature(stmt_expr_attributes)]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 pub mod util {

compiler/rustc_ast_ir/Cargo.toml

@@ -19,6 +19,3 @@ nightly = [
     "dep:rustc_macros",
     "dep:rustc_span",
 ]
-
-[lints]
-workspace = true

compiler/rustc_ast_ir/src/lib.rs

@@ -9,6 +9,7 @@
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", feature(never_type))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
+#![warn(unreachable_pub)]
 // tidy-alphabetical-end
 
 #[cfg(feature = "nightly")]