[llvm] [VectorCombine] foldShuffleOfBinops - fold shuffle(binop(shuffle(x),shuffle(z)),binop(shuffle(y),shuffle(w)) -> binop(shuffle(x,z),shuffle(y,w)) (PR #120984)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

> > @RKSimon It looks like [af83093](https://github.com/llvm/llvm-project/commit/af83093933ca73bc82c33130f8bda9f1ae54aae2) causes an llvm-test-suite hang in ReleaseLTO-g configuration.
> 
> I'll revert - I'm still on holiday break and don't have much time to look at this right now.

This one also hangs https://lab.llvm.org/buildbot/#/builders/66/builds/8059

https://github.com/llvm/llvm-project/pull/120984