panfrost: Launch transform feedback shaders

We now have infrastructure in place to generate variants of vertex shaders
specialized for transform feedback. All that's left is launching these
compute-like kernels before the IDVS job, implementing both the
transform feedback and the regular rasterization pipeline. This implements
transform feedback on Valhall, passing the relevant GLES3.1 tests.

Signed-off-by: Alyssa Rosenzweig <>
Part-of: <!15720>
183 jobs for !15720 with play-xfb-5 in 46 minutes and 52 seconds (queued for 48 seconds)
latest merge request