[IO] Made one more attempt (this time more verbose) to avoid signedness assignment problems in Parrot_io_peek_buffer(), reported by Coverity Scan as CID #148.
[IO] Made one more attempt (this time more verbose) to avoid signedness
assignment problems in Parrot_io_peek_buffer(), reported by Coverity Scan as
CID #148.

git-svn-id: 6e74a02f85675cec270f5d931b0f6998666294a3@33501 d31e2699-5ff4-0310-a27c-f18f2fbe73fe

ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot,ashgti/parrot