This lets us get coverage of corner cases of the driver that are tricky to
force a testcase to hit. We don't want to do a full run of the CTS with
each option because that's a lot of runner time, so stack a bunch of
fractional runs in one test job to amortize the test run setup overhead.
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4621>
Eric Anholt