Remark val_lessdef_normalize:
  forall v v' ty,
  Val.has_type v ty -> Val.lessdef v v' ->
  Val.lessdef v (Val.load_result (chunk_of_type ty) v').

Lemma compat_left_sound: forall r l e q, compat_left r l e = true -> EqSet.In q e -> ereg q = r -> ekind q = Full /\ eloc q = l.