c57a932c3f
Move the cast_float_to_int fallback code to GCC Now that we require at least LLVM 13, that codegen backend is always using its intrinsic `fptosi.sat` and `fptoui.sat` conversions, so it doesn't need the manual implementation. However, the GCC backend still needs it, so we can move all of that code down there.
Please read the rustc-dev-guide chapter on Backend Agnostic Codegen.