[libclc] [libclc] Reduce bithacking in CLC frexp (PR #129871)

[Romaric Jodin via cfe-commits]

rjodinchr wrote:

I've deployed that patch into ChromeOS, and now Intel, Qualcomm and Imagination are also failing. I need to have a closer look to see if anything can be changed in `clspv` to fix it, but I might end-up needing the fix mentioned a few weeks ago.

https://github.com/llvm/llvm-project/pull/129871