aco: fix C++11/C++14 compilation

static_assert without a message is only available since C++17.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Fixes: d1f992f3c2d ('aco: rework barriers and replace can_reorder')
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3374
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6216>
1 file changed