[llvm] [SLP] Initial vectorization of non-power-of-2 ops. (PR #77790)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

Updated to add non-power-of-2 VF based on https://github.com/llvm/llvm-project/pull/82793

https://github.com/llvm/llvm-project/pull/77790