[PATCH] x86_64: Don't define string functions to builtin

gcc should handle this anyways, and it causes problems when
sprintf is turned into strcpy by gcc behind our backs and
the C fallback version of strcpy is actually defining __builtin_strcpy

Then drop -ffreestanding from the main Makefile because it isn't
needed anymore and implies -fno-builtin, which is wrong now.
(it was only added for x86-64, so dropping it should be safe)

Noticed by Roman Zippel

Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>