[libcxx-commits] [libcxx] [libc++][math] Add `constexpr` to `copysign` functions (PR #216285)

[Lucas Mellone via libcxx-commits]

lknknm wrote:

> Also, I don't really understand why you're trying so hard to make it work in the library instead of just updating Clang. I'm pretty sure it's not that hard if the builtin is already constexpr.

I can try, but I'm not sure about the process for these specifically, nor if they need `libc` implementations for `meowl` and `meowf` as I said. If you can we can try to work on this together / I can ask you questions directly on how to work on updating Clang. 

https://github.com/llvm/llvm-project/pull/216285