[clang] [clang] Allow `pragma float_control(precise, *)` to... (PR #105912)

[Zahira Ammarguellat via cfe-commits]

zahiraam wrote:

Not very clear to me what the issue is. Can you please explain this in the description. I think here the `#pragma float_control(precise, on)` should be taking precedence over the `-ffast-math` flag and it's not. Right? 

https://github.com/llvm/llvm-project/pull/105912