bootstrap: simplify setting unstable-options for tools

We unconditionally set this to avoid recompiling tools between
`x check $tool` and `x test $tool` executions.

See rust-lang#116538 for more information.

Signed-off-by: onur-ozkan <[email protected]>

Author: onur-ozkan

src/bootstrap/src/core/build_steps/check.rs

@@ -463,10 +463,6 @@ macro_rules! tool_check_step {
                     cargo.arg("--all-targets");
                 }
 
-                // Enable internal lints for clippy and rustdoc
-                // 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");
                 let _guard = builder.msg_check(&concat!(stringify!($name), " artifacts").to_lowercase(), target);
                 run_cargo(
                     builder,

src/bootstrap/src/core/build_steps/tool.rs

@@ -203,6 +203,16 @@ pub fn prepare_tool_cargo(
     if !features.is_empty() {
         cargo.arg("--features").arg(&features.join(", "));
     }
+
+    // Enable internal lints for clippy and rustdoc
+    // 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
+    //
+    // NOTE: We unconditionally set this here to avoid recompiling tools between `x check $tool`
+    // and `x test $tool` executions.
+    // See https://github.com/rust-lang/rust/issues/116538
+    cargo.rustflag("-Zunstable-options");
+
     cargo
 }