[llvm] [LoopInterchange] Remove 'S' Scalar Dependencies (PR #119345)

[Sjoerd Meijer via llvm-commits]

https://github.com/sjoerdmeijer commented:

> The implementation looks good to me. but some tests do not appear to have achieved their original objectives. I'm not sure what we should do in such cases, but in my opinion a mechanical update does not make sense. Marking `XFAIL` may be one option.

Thanks, and I also had a bit of a nagging feeling about the test cases. I quite like the idea about the XFAILs. I think what I will do is the following:
- I will first convert the test cases that were modified and check the full IR to tests that check the optimisation remark in a separate patch. Checking the the optimisation remark is more compact, less verbose and easier to see. 
- I will then see if adding XFAILS here is better, I think so. 

https://github.com/llvm/llvm-project/pull/119345