[llvm] [ConstantFolding] Add ilogb in isMathLibCallNoop (PR #122582)

[Kshitij Paranjape via llvm-commits]

kshitijvp wrote:

Thanks, I will surely make this change in another patch, can you share your WIP implementation if possible? I want to make more contributions and learn more :)

https://github.com/llvm/llvm-project/pull/122582