[llvm] [WebAssembly] Fix signatures of frexpf family of libcalls (PR #133289)

[Derek Schuff via llvm-commits]

dschuff wrote:

Cloning seems OK.
I suppose the "real" best longterm solution would be to somehow infer the libcall signatures, although there wasn't an easy way to do it when I wrote this in the first place, since the type lowering code is buried in codegen and I'm not sure how hard it would be to extract. There have been 9 changes to this file in the past 2 years, which seems like somewhere between "no maintenance burden/risk" and "definitely worth fixing".

https://github.com/llvm/llvm-project/pull/133289