Hint Rewrite int_repr_byte_signed_eq: norm entailer_rewrite.

Lemma typed_false_negb_bool_val_p:
forall p,
is_pointer_or_null p ->
typed_false tint
(force_val
(option_map (fun b : bool => Val.of_bool (negb b))
(bool_val_p p))) ->
isptr p.