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

[Alexey Bataev via llvm-commits]

https://github.com/alexey-bataev commented:

Would be good to see more tests for other targets. May help to check that TTI does not crash and vectorizatyion works for these targets too.

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