Spellchecking compiler comments

This PR cleans up the rest of the spelling mistakes in the compiler comments. This PR does not change any literal or code spelling issues.

compiler/rustc_lint/src/noop_method_call.rs

@@ -64,7 +64,7 @@ impl<'tcx> LateLintPass<'tcx> for NoopMethodCall {
         let substs = cx.typeck_results().node_substs(expr.hir_id);
         if substs.needs_subst() {
             // We can't resolve on types that require monomorphization, so we don't handle them if
-            // we need to perfom substitution.
+            // we need to perform substitution.
             return;
         }
         let param_env = cx.tcx.param_env(trait_id);