[Piglit] [PATCH v2 6/6] gs: Adapt xfb/intervening-read.c for geometry shaders.

[Chad Versace]

Patches 1, 2, 3, and 5 are
Reviewed-by: Chad Versace <chad.versace at linux.intel.com>

As you already know, patches 3 and 5 may prevent those tests from
running on NVidia, even if they did previously ran. I think that
outcome is warranted here, as long we follow through with the
fix to core Piglit for 3.1 contexts we discussed.

Patches 4 and 6, I know too little about GS to review them. Maybe
this indicates that it's about time that I learn GS.