llvmpipe anisotropic texture filtering
This adds anisotropic texture filtering using the same method as the softpipe code to llvmpipe.
It passes CTS (not great), and seem to operate the same way as softpipe in mipmap_tunnel and texfilt.
I'm not sure the softpipe implementation is as correct as it could be and one of the traces that fails here looks to have a drop off one level 0->level1 if I was guessing, I'd like to reproduce the traces with softpipe maybe.
Edited by Dave Airlie