kBitmap's kernel signature is incorrect and out of sync with the
signatures of its sub operations, causing valid calls to subop #1
(BitmapDestroy) to fail. BitmapDestroy allows an invalid reference
to be passed, which GK1 Mac does when decoding the Rada drums in
room 410, but kBitmap's signature doesn't.
Fixed by applying the correct signature, which is the same as kFileIO
which has a similar structure: require an integer for the subop and
then allow anything, including invalid references.
97cb7ce521