x86-32: Add new pt_regs stubs

Add new stubs which add the pt_regs pointer as the last arg, matching
64-bit.  This will allow these syscalls to be easily merged.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1260403316-5679-2-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>