Use this to test that path of invalidation. This test actually shows
redundant invalidation here that is really bad. I'm going to work on
fixing that next, but wanted to commit the test harness now that its all
working.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225257 91177308-0d34-0410-b5e6-96231b3b80d8