Rollup merge of #99401 - TaKO8Ki:avoid-symbol-to-&str-conversions, r=nnethercote

Avoid `Symbol` to `&str` conversions

`Symbol::as_str` is a slowish operation, so this patch removes some usages of it.

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs

@@ -228,7 +228,7 @@ pub fn suggest_adding_lifetime_params<'tcx>(
     if is_impl {
         sugg.push_str(" and update trait if needed");
     }
-    err.multipart_suggestion(sugg.as_str(), suggestions, Applicability::MaybeIncorrect);
+    err.multipart_suggestion(sugg, suggestions, Applicability::MaybeIncorrect);
 
     true
 }