x86 atomic operations: atomic_or_long() atomic_inc_short()

Provide atomic operations for increment of a 16-bit integer and
logical OR into a 64-bit integer.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>