[llvm] [Delinearization] Remove tryDelinearizeFixedSizeImpl (PR #169046)

[Michael Kruse via llvm-commits]

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

LGTM, Polly not affected (you would see that in the pre-merge CI failing)

Working on removing `getIndexExpressionsFromGEP` from Polly. The problem I encountered is that the matrix-multiplication pattern recognition relies on multi-dimensional accesses. Detecting the pattern with linearized accesses is not so easy.

https://github.com/llvm/llvm-project/pull/169046