[Bug libstdc++/54005] Use __atomic_always_lock_free in libstdc++ is_lock_free instead of __atomic_is_lock_free

[hp at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54005

--- Comment #12 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-08-28 
21:59:55 UTC ---
(In reply to comment #11)
> Andrew I'll revert

Then please set the object pointer to NULL in the __atomic_is_lock_free
 call.