radv: fix gathering XFB info if there is dead outputs
The driver should still gather XFB info even if all XFB outputs are dead, otherwise the pipeline can't find the streamout shader. RADV should use vk_spirv_to_nir() at some point to reduce code duplication during SPIRV->NIR compilation. This fixes new dEQP-VK.transform_feedback.simple.*. Cc: mesa-stable Signed-off-by:Samuel Pitoiset <samuel.pitoiset@gmail.com> Reviewed-by:
Mike Blumenkrantz <michael.blumenkrantz@gmail.com> Part-of: <mesa/mesa!17939>