Summary:
This makes it very easy to test files that only differ in a constant
value somewhere in the test case.
Reviewers: jlebar, hfinkel, chandlerc, probinson
Reviewed By: probinson
Subscribers: probinson, llvm-commits
Differential Revision: https://reviews.llvm.org/D39629
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@317572 91177308-0d34-0410-b5e6-96231b3b80d8