Rollup merge of #122813 - nnethercote:nicer-quals, r=compiler-errors

Qualifier tweaking

Adding and removing qualifiers in some cases that make things nicer. Details in individual commits.

r? `@compiler-errors`

compiler/rustc_middle/src/mir/mod.rs

@@ -1545,7 +1545,7 @@ pub struct SourceScopeData<'tcx> {
 #[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable)]
 pub struct SourceScopeLocalData {
     /// An `HirId` with lint levels equivalent to this scope's lint levels.
-    pub lint_root: hir::HirId,
+    pub lint_root: HirId,
 }
 
 /// A collection of projections into user types.