Implement compare_exchange and compare_exchange_weak#30969

Merged

bors merged 3 commits intorust-lang:masterfrom Amanieu:extended_atomic_cmpxchg

Feb 22, 2016

+577-49

Commits on Feb 18, 2016

Commits on Feb 22, 2016

Add a test to make sure trans doesn't choke on any of the intrinsics
Amanieu
committed