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

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

I've created #139878 to see if we can get the baseline tests added to trunk (and using the update_llc_test_checks script) to make it easier to see the codegen diffs

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