[PATCH] Use __sync_add_and_fetch and __sync_sub_and_fetch when they are available

[Jason Evans]

On Mar 26, 2012, at 8:03 AM, Mike Hommey wrote:
> From: Mike Hommey <mh at glandium.org>
> 
> These functions may be available as inlines or as libgcc functions. In the
> former case, a __GCC_HAVE_SYNC_COMPARE_AND_SWAP_n macro is defined. But we
> still want to use these functions in the latter case, when we don't have
> our own implementation.

Applied; thanks.

Jason