[Mesa-dev] i965 optimizations and one for core GLSL

[Eric Anholt]

I came up with a patch to improve Lightsmark performance 0.9% by using
"MRF"s round-robin.  But that's just layering hacks on hacks, so I
decided to convert texturing to using GRFs on gen7.  That resulted in
a big regression due to the lame register coalescing, which led to
fixing that, which led to a regression, etc., and here we are.

I'm totally going to actually finish that GRF texturing patch tomorrow.