Copy x86_64 and add a head32.c so we can start moving early
architecture initialization out of assembly.

[ Sam Ravnborg <sam@ravnborg.org>: updated it to x86 ]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>