[Mesa-dev] MR: Some softpipe fixes

[Gert Wollny]

Hi Roland, 

I did some softpipe patches, maybe you could take a look?

Fixing LOD evaluation, cube face selection, and add support for 
explicit derivatives: 
https://gitlab.freedesktop.org/mesa/mesa/merge_requests/702

On top of that (i.e. the MR includes the above) 

Softpipe add support for TGSI_OPCODE_INTERP_* and raise GLSL level to
4.0: 
https://gitlab.freedesktop.org/mesa/mesa/merge_requests/725

I'm not sure whether we really want to raise the GLSL 4.0 before we
land real MSAA support, but it also exposes OES_geometry_shader and a
few other things that are of interest. I think the fixes for texturing
should definitely land before doing this, that's why I put the series
that does that on top of !702.  

Many thanks, 
Gert