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

[Jake Egan via llvm-commits]

jakeegan wrote:

@c8ef The result is:
```
define noundef double @f() local_unnamed_addr #0 {
entry:
  ret double 0.000000e+00
}
```
It seems this will require more investigation on an AIX machine, so I'll XFAIL the test on AIX and investigate further.

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