Tests: Use CHECK-LABEL where possible

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192403 91177308-0d34-0410-b5e6-96231b3b80d8
Tests: Do not unnecessarily depend on kill comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192404 91177308-0d34-0410-b5e6-96231b3b80d8