This patch defines frame_pointer() and stack_pointer() similar to the
already defined instruction_pointer(). Thus the oprofile code can be
written in a more readable fashion.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NJan Blunck <jblunck@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>