Update Gallium opcodes
This series update the Gallium opcodes to be coherent with Mesa. As virglrenderer Gallium differ from the Mesa one, I just import the interesting bit.
This will be useful for adding ARB_gpu_shader_int64 for example.
PS: Looking at the opcode, it seems that we don't do anything for a bunch of opcode. Maybe those opcode are very rare but it still scary.