v3d: Hook up some shader-db output to GL_ARB_debug_output.

v3d: Hook up some shader-db output to GL_ARB_debug_output.

This allows the original shader-db project's run.c runner to parse things
easily, and is probably a good thing to have for GL_ARB_debug_output in
general.  I formatted it more like Intel's so I can mostly reuse their
report script.