Southern Islands gallium support

I've gone ahead and pushed the initial SI gallium driver to my mesa tree on fdo. The new driver is called radeonsi. I've left it in my personal repo for now as Tom wants to restructure the llvm stuff before we merged it into mesa proper. You can find the code here (http://cgit.freedesktop.org/~agd5f/mesa) on the radeonsi branch once cgit picks up the new repo.

Basic egl demos are starting to run. There is no ddx for SI right now. The plan is to support X acceleration via gallium.

The shader ISA documentation is also getting finished up and should be out soon.

git://people.freedesktop.org/~agd5f/mesa ssh://people.freedesktop.org/~agd5f/mesa

Alex