[llvm] [InstCombine] Drop Range attribute when simplifying 'fshl' based on demanded bits (PR #124429)

[Fangrui Song via llvm-commits]

MaskRay wrote:

Thanks!
Read https://llvm.org/docs/InstCombineContributorGuide.html#precommit-tests . Precommited the test and rebased.

https://github.com/llvm/llvm-project/pull/124429