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 can_undef_except_sound:
forall lx e ml q,
can_undef_except lx ml e = true -> EqSet.In q e -> Loc.diff (eloc q) lx -> Loc.notin (eloc q) (map R ml).