When I last time fixed this, I missed that continuing here would make us
leak pointers in the translate state, which is what made this avoid a
crash in the first place.
That's not great, we need to set *some* pointer in this case. The
obvious option would be NULL, but that means that the translate-code
also needs to support NULL-pointers here.
Instead, let's point to a small, static buffer that contains enough
zero-data for the largest possible vertex attribute. This avoids having
to add more NULL-checks.
Fixes: a8e8204b18 ("gallium/u_vbuf: support NULL-resources")
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7773>