[llvm] [Github][RFC] Add workflow to diff codegen on llvm-test-suite (PR #190010)

[Tom Stellard via llvm-commits]

https://github.com/tstellar approved this pull request.

Thanks for making the changes.  I have no  more feedback, but you should wait for the other reviewers before committing.

https://github.com/llvm/llvm-project/pull/190010