[Mesa-dev] ARB_blend_func_extended mesa/gallium patches

[Dave Airlie]

This set doesn't contain any driver support, I've gotten softpipe mostly working
(it fails one of my piglit tests) and r600g passes all of them.

The bit I'm most unsure about is the GLSL support, since I can't find hw that
does more than 1 dual-source RT, so I've no idea how they would expect the
shader outputs to be ordered if dual-source MRT ever existed.

I think wrt piglit coverage I've covered most of the extension, though
I just noticed I haven't done an ARB_explicit_attrib_location test where
it interacts with this, so I'll take a look at that later.

Dave.