intel/compiler: Set divergence analysis options

Although we don't use divergence analysis yet, we've had several
work-in-progress series that make use of it.  We may as well set
our options so that those series can assume they're in place.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15484>
1 file changed