Do we need the glBindImageTexture() (and corresponding binding in compiler_shader()) in the OpenGL runner? I would have expected the combined sampler binding to be sufficient on its own.
Oh, right, that is not necessary.
Oops, looks like I left in a debug trace()...
I removed the trace() message while at it then.
I also realizer that I was incorrectly passing `gl_resource(resource)->id` instead of `gl_resource(resource)->tbo_id` to glBindTexture() for buffers, and I added an extra test.