Everything looks good, this will enable us to work on bunch of small
corners of gles 3.1 even though some of the extensions are still being
baked.
I sent small comment to patch #2 which you can feel free to ignore, I've
been reading ES spec a lot lately so happened to notice that I'm reading
The first two patches are just re-re-sends of the same patches.
Based on feedback from Emil and others, I changed the later patches to
use a new environment variable, MESA_GLES_VERSION_OVERRIDE, to override
GLES versions. I considered naming this MESA_GLES2_VERSION_OVERRIDE so
that we could later
