x86: x86 user_regset_view

This defines task_user_regset_view and the tables
describing the x86 user_regset layouts for 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>