[Patch] Use __GCC_HAVE_SYNC_COMPARE_AND_SWAP_*

[Peter Dimov]

Benjamin Kosnik wrote:

>> 2007-05-24  Paolo Carlini  <pcarlini@suse.de>
>>
>> * include/ext/concurrence.h: Use __GCC_HAVE_SYNC_COMPARE_AND_SWAP_*.
>
> Excellent news indeed.

The macros seem pretty useful. Are they going to be in 4.3? I'm converting 
some boost::shared_ptr code to use __sync_* and running into the i386 
'unresolved __sync_..._4' problem. What is the usual way to deal with that?