[llvm] [GlobalISel] Combine (X >> C) << C to X & ((-1 >> C) << C) (PR #114821)

[Dávid Ferenc Szabó via llvm-commits]

dfszabo wrote:

> There are no hits in the existing test? Looks kinda artificial.

https://godbolt.org/z/vf9EsrfdG

SelectionDAG handles it.

https://github.com/llvm/llvm-project/pull/114821