Auto merge of rust-lang#139588 - Kobzol:rust-analyzer-opt, r=<try>

Apply LTO when building rust-analyzer

Trying if LTO/PGO can help RA's performance, and by how much.

CC `@Veykril` I realized that we don't even do LTO for Rust Analyzer, that could be a very low hanging fruit to improve its performance 😅

try-job: dist-x86_64-linux

Author: bors

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

@@ -148,7 +148,9 @@ impl Step for ToolBuild {
             &self.extra_features,
         );
 
-        if path.ends_with("/rustdoc") &&
+        // Rusc tools (miri, clippy, cargo, rustfmt, rust-analyzer)
+        // could use the additional optimizations.
+        if self.mode == Mode::ToolRustc &&
             // rustdoc is performance sensitive, so apply LTO to it.
             is_lto_stage(&self.compiler)
         {