vrend: Add a few more swizzles to texture buffer fetches

For some reason these don't seem to happen automatically, so add the
fill values for these textures.

Fixes KHR-GL43.shader_image_load_store.advanced-sync-imageAccess

Signed-off-by: Gert Wollny <gert.wollny@collabora.co.uk>
Part-of: <https://gitlab.freedesktop.org/virgl/virglrenderer/-/merge_requests/1166>
1 file changed