Hint Resolve valid_val_longofwords : wd.

Lemma extcall_arg_pair_valid:
forall f rs m locs arg
(Hrs_wd: regset_wd f rs)
(Hmem_wd : valid_mem m)
(Hobs_eq: domain_memren f m)
(Harg: extcall_arg_pair rs m locs arg),
valid_val f arg.