Fix grammar.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187755 91177308-0d34-0410-b5e6-96231b3b80d8
FileCheckize some of the testcases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187756 91177308-0d34-0410-b5e6-96231b3b80d8