[llvm] Added fix to enable constant folding that is missing for math library functions (scalbln , scalbn, ldexp) (PR #169893)

[via llvm-commits]

fawdlstty wrote:

Consider referencing PR <https://github.com/llvm/llvm-project/pull/114417> and adding corresponding tests

https://github.com/llvm/llvm-project/pull/169893