Rollup merge of #84484 - jyn514:check-tools, r=Mark-Simulacrum

Don't rebuild rustdoc and clippy after checking bootstrap

This works by unconditionally passing -Z unstable-options to the
compiler. This has no affect in practice since bootstrap doesn't use
`deny(rustc::internal)`.

Fixes https://github.com/rust-lang/rust/issues/82461.

r? ```@Mark-Simulacrum```

src/bootstrap/check.rs

@@ -321,11 +321,9 @@ macro_rules! tool_check_step {
                 }
 
                 // Enable internal lints for clippy and rustdoc
-                // NOTE: this intentionally doesn't enable lints for any other tools,
-                // see https://github.com/rust-lang/rust/pull/80573#issuecomment-754010776
-                if $path == "src/tools/rustdoc" || $path == "src/tools/clippy" {
-                    cargo.rustflag("-Zunstable-options");
-                }
+                // NOTE: this doesn't enable lints for any other tools unless they explicitly add `#![warn(rustc::internal)]`
+                // See https://github.com/rust-lang/rust/pull/80573#issuecomment-754010776
+                cargo.rustflag("-Zunstable-options");
 
                 builder.info(&format!(
                     "Checking stage{} {} artifacts ({} -> {})",

src/librustdoc/lib.rs

@@ -16,7 +16,7 @@
 #![feature(type_ascription)]
 #![feature(iter_intersperse)]
 #![recursion_limit = "256"]
-#![deny(rustc::internal)]
+#![warn(rustc::internal)]
 
 #[macro_use]
 extern crate lazy_static;

src/tools/clippy/clippy_lints/src/lib.rs

@@ -17,7 +17,7 @@
 // warn on lints, that are included in `rust-lang/rust`s bootstrap
 #![warn(rust_2018_idioms, unused_lifetimes)]
 // warn on rustc internal lints
-#![deny(rustc::internal)]
+#![warn(rustc::internal)]
 
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently there is no way to opt into sysroot crates without `extern crate`.)

src/tools/clippy/src/driver.rs

@@ -4,7 +4,7 @@
 // warn on lints, that are included in `rust-lang/rust`s bootstrap
 #![warn(rust_2018_idioms, unused_lifetimes)]
 // warn on rustc internal lints
-#![deny(rustc::internal)]
+#![warn(rustc::internal)]
 
 // FIXME: switch to something more ergonomic here, once available.
 // (Currently there is no way to opt into sysroot crates without `extern crate`.)