Revert "Auto merge of #89709 - clemenswasser:apply_clippy_suggestions_2, r=petrochenkov"

The PR had some unforseen perf regressions that are not as easy to find.
Revert the PR for now.

This reverts commit 6ae8912a3e, reversing
changes made to 86d6d2b738.

compiler/rustc_data_structures/src/stack.rs

@@ -5,7 +5,6 @@ const RED_ZONE: usize = 100 * 1024; // 100k
 
 // Only the first stack that is pushed, grows exponentially (2^n * STACK_PER_RECURSION) from then
 // on. This flag has performance relevant characteristics. Don't set it too high.
-#[allow(clippy::identity_op)]
 const STACK_PER_RECURSION: usize = 1 * 1024 * 1024; // 1MB
 
 /// Grows the stack on demand to prevent stack overflow. Call this in strategic locations