[virglrenderer-devel] ARB_texture_view support

[Dave Airlie]

This enables the guest to use ARB_texture_view with the corresponding
guest patch which I'll send shortly. (ARB_texture_view is part of GL4.3).

This doesn't cause any regressions in my piglit run on skylake, it
has some fails around the 3 component formats which don't seem to be
directly related to texture views, so I'd rather not block on fixing
them as I think we have other issues in that area.

Dave.