[llvm] [ConstantFold] Fold `log1p` and `log1pf` when the input parameter is a constant value. (PR #112113)

[via llvm-commits]

c8ef wrote:

The current constant folding of the `log1p` function relies on the host's libc to compute the folded result. I'm not very familiar with the Power platform. Does its implementation differ from x86 or AArch64, particularly in handling positive or negative zero?

https://github.com/llvm/llvm-project/pull/112113