Geometry & Tessellation Shaders For Mesa's OpenGL Compatibility Context

With the recent Mesa 18.1 release there is OpenGL 3.1 support with the ARB_compatibility context for the key Gallium3D drivers, but Marek Olšák at AMD continues working on extending that functionality under the OpenGL compatibility context mode.

Marek has sent out a set of eight patches that provide basic support in the OpenGL compatibility mode for handling geometry shaders and tessellation shaders. This support should work as long as they are not combined with non-GLSL stages.

The patches for now can be found on Mesa-dev but hopefully it won't be long before having this extended functionality available from Mesa 18.2 Git.