Don't normalize constants unless they need normalization

Author: compiler-errors

compiler/rustc_trait_selection/src/traits/project.rs

@@ -638,6 +638,10 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> {
         if tcx.lazy_normalization() {
             constant
         } else {
+            if !constant.needs_normalization(self.param_env.reveal()) {
+                return constant;
+            }
+
             let constant = constant.super_fold_with(self);
             debug!(?constant, ?self.param_env);
             with_replaced_escaping_bound_vars(

compiler/rustc_trait_selection/src/traits/query/normalize.rs

@@ -360,6 +360,10 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> {
         &mut self,
         constant: ty::Const<'tcx>,
     ) -> Result<ty::Const<'tcx>, Self::Error> {
+        if !constant.needs_normalization(self.param_env.reveal()) {
+            return Ok(constant);
+        }
+
         let constant = constant.try_super_fold_with(self)?;
         debug!(?constant, ?self.param_env);
         Ok(crate::traits::project::with_replaced_escaping_bound_vars(