[llvm] [DAGCombiner] Fold pattern for srl-shl-zext (PR #138290)

[Craig Topper via llvm-commits]

topperc wrote:

> Fold (srl (lop x, (shl (zext y), c1)), c1) -> (lop (srl x, c1), (zext y))

The shifts cancel out in the source pattern. How can there still be a shift in the result pattern?

https://github.com/llvm/llvm-project/pull/138290