r600: Fix some gles 3.1 CTS tests
This series fixes tests out of
dEQP-GLES31.functional.compute.shared_var.basic_type.*
dEQP-GLES31.functional.shaders.opaque_type_indexing.ubo.*
dEQP-GLES31.functional.shaders.multisample_interpolation.interpolate_at_sample.centroid_qualified.multisample_*
dEQP-GLES31.functional.compute.shared_var.basic_type.*
adds support for helper invocations, and cleans up some code how uniforms and literals are handled.
Edited by Gert Wollny