[llvm] [SCEV] Commute sign extends through nsw multiplication (PR #163840)

[Alireza Torabian via llvm-commits]

1997alireza wrote:

Currently, a couple of test cases are failed after this change and need to be fixed.

```  LLVM :: CodeGen/AArch64/sinksplat.ll
  LLVM :: CodeGen/X86/avx512vnni-combine.ll
  LLVM :: CodeGen/X86/avxvnni-combine.ll
  LLVM :: Transforms/IndVarSimplify/add-nsw-zext-fold.ll
  LLVM :: Transforms/LoopStrengthReduce/X86/pr47776-do-not-apply-info-from-guards-to-addrecs.ll
  LLVM :: Transforms/LoopUnroll/runtime-loop-multiple-exits.ll```

https://github.com/llvm/llvm-project/pull/163840