[llvm] Reapply "[SelectionDAG] Recurse through mask expression trees in WidenVSELECTMask" (PR #217307)

[Valeriy Savchenko via llvm-commits]

SavchenkoValeriy wrote:

Hello @mikaelholmen, thanks for reporting it, I'll look into it ASAP

https://github.com/llvm/llvm-project/pull/217307