[llvm] [DAG] Propagate OrZero and DemandedElts for min/max in isKnownToBeAPowerOfTwo (PR #182369)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

lit tests that show codegen impact would be preferable to unit tests 

https://github.com/llvm/llvm-project/pull/182369