vtn/opencl: Switch division-related ops to use libclc

Specifically, fmod only uses libclc if it was going to be lowered.
Also, add missing half_divide and half_recip handling.

Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6035>
1 file changed