[llvm] [Delinearization] Add function for fixed size array without relying on GEP (PR #145050)

[Sjoerd Meijer via llvm-commits]

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

I think this makes a lot of sense.

Give it a day or 2 before merging this in case @sebpop has more comments.

https://github.com/llvm/llvm-project/pull/145050