Summary: Add tests for all atomic operations for powerpc64le, so that all changes can be easily examined.
Reviewers: kbarton, hfinkel, echristo
Subscribers: mehdi_amini, nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D31285
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298614 91177308-0d34-0410-b5e6-96231b3b80d8
