x86_64: don't use weak symbols on x86-64

x86_64: don't use weak symbols on x86-64

Various gcc versions inline functions that are both weak and hidden,
without even giving a warning.

Certainly the risk exists that we'll see the problem again when
another weak function gets introduced, but I don't see a way to
protect us from that.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Just remove the weak attribute altogether. It's the only one in
non-ia64-specific code. We can get teh same effect with ifdefs which
although a bit unsightly is better than using compiler/linker features
we cannot trust.

Signed-off-by: Keir Fraser <keir@xen.org>