Do not normalize unconditionally in lower_const_arg

Author: voidc

compiler/rustc_hir_typeck/src/expr.rs

@@ -1718,7 +1718,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let count_span = count.span();
         let count = self.try_structurally_resolve_const(
             count_span,
-            self.lower_const_arg(count, FeedConstTy::No),
+            self.normalize(count_span, self.lower_const_arg(count, FeedConstTy::No)),
         );
 
         if let Some(count) = count.try_to_target_usize(tcx) {

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -497,7 +497,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.tcx.hir().span(const_arg.hir_id),
             ObligationCauseCode::WellFormed(None),
         );
-        self.normalize(const_arg.span(), ct)
+        ct
     }
 
     // If the type given by the user has free regions, save it for later, since