From the newsgroup: hero poly'd into various monster forms would be
incapable of turning a target to stone when wielding a cockatrice corpse.
Monster forms with a claw attack as their very first attack (second for
incubus and sucubus, handled as a special case) would have that be
converted into a weapon attack. But some monster forms start with bite
attacks and have their claw attacks later; a hero poly'd into such form
wouldn't use his/her wielded weapon.
This fixes that, but it's actually academic (or about to become so).
The only monster capable of wielding a weapon which would then be ignored
was jabberwock, and I think leaving NOHANDS off the jabberwock definition
is a bug in itself (next patch...).