End WITH_SHARE.

(* Lemma data_at_type_changable: forall (sh: Share.t) (t1 t2: type) v1 v2, t1 = t2 -> JMeq v1 v2 -> data_at sh t1 v1 = data_at sh t2 v2. *)
Lemma by_value_default_val: forall t:type,
type_is_by_value t = true -> JMeq (default_val t) Vundef.