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

[Hubert Tong via llvm-commits]

hubert-reinterpretcast wrote:

> Marking it as `XFAIL: target={{.*}}-aix{{.*}}` will be sufficient?

The XFAIL is actually wrong. The real issue is that compiling for a non-AIX target on an AIX machine will not generate the negative zero result.

A possible solution is to add the special cases to the constant-folding code in LLVM.

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