[llvm] [LLVM] Improve the DemandedBits Analysis (PR #148853)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

Thanks for the patch! Can you split the improvements, one per operation, so we can ensure that each change has sufficient test coverage?

https://github.com/llvm/llvm-project/pull/148853