[llvm] Swap UnrollAndJam Pass to before the SLP Vectorizer Pass (PR #97029)

[Nikita Popov via llvm-commits]

https://github.com/nikic commented:

Please add a test in llvm/test/Transforms/PhaseOrdering that shows why changing the pipeline position is useful.

https://github.com/llvm/llvm-project/pull/97029