Add some tests for NVPTX lowering of cmpxchg


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213586 91177308-0d34-0410-b5e6-96231b3b80d8
Rename metadata llvm.loop.vectorize.unroll to llvm.loop.vectorize.interleave.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213588 91177308-0d34-0410-b5e6-96231b3b80d8