[llvm] VectorWiden pass to widen aleady vectorized instrctions (PR #67029)

[Sander de Smalen via llvm-commits]

https://github.com/sdesmalen-arm requested changes to this pull request.

Just a general observation that the last patch in this pull-request had quite a few code changes, but no changes to any of the tests. That suggests the test-coverage of the pass is too limited.

https://github.com/llvm/llvm-project/pull/67029