Jan asked to always use the builtin memcpy on gcc 4.3 mainline because
it should generate better code than the old macro. Let's try it.

Cc: Jan Hubicka <jh@suse.cz>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>