glamor: add EXT_gpu_shader4 support
This enables a number of the GLSL 1.30 paths on GPUs that have
EXT_gpu_shader4 but don't have GLSL 1.30 exposed.
(Intel gen4/5 mainly)
Reviewed-by: 
Adam Jackson <ajax@redhat.com>
This enables a number of the GLSL 1.30 paths on GPUs that have
EXT_gpu_shader4 but don't have GLSL 1.30 exposed.
(Intel gen4/5 mainly)
Reviewed-by: Adam Jackson <ajax@redhat.com>