Include the host architecture's ptrace-abi.h instead of ptrace.h.

There was some cpp mangling of names around the ptrace.h include to avoid
symbol clashes between UML and the host architecture.  Most of these can go
away.  The exception is struct pt_regs, which is convenient to have in
userspace, but must be renamed in order that UML can define its own.

ptrace-x86_64.h needed to have some now-obsolete cpp cruft and a declaration
removed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>