panfrost: Revert provoking vertex assertion

b6a30b72ab ("panfrost: Implement provoking vertices on Valhall") added an
assertion that every draw selects a particular provoking vertex. The intent was
to ensure provoking vertex selection actually happened. Unfortunately, the
assertion is too strong, as the provoking vertex is irrelevant for some (most)
draws. For those, we don't *want* to commit to a particular provoking vertex for
those to avoid flushing.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17430>

src/gallium/drivers/panfrost/pan_cmdstream.c

@@ -3101,13 +3101,6 @@ panfrost_batch_get_bifrost_tiler(struct panfrost_batch *batch, unsigned vertex_c
 
         mali_ptr heap = t.gpu;
 
-        /* We emit this descriptor after the first draw. The provoking vertex
-         * for the batch should have already been set (on Valhall, where it is a
-         * property of the batch).
-         */
-        if (PAN_ARCH >= 9)
-                assert(pan_tristate_is_defined(batch->first_provoking_vertex));
-
         t = pan_pool_alloc_desc(&batch->pool.base, TILER_CONTEXT);
         GENX(pan_emit_tiler_ctx)(dev, batch->key.width, batch->key.height,
                                  util_framebuffer_get_num_samples(&batch->key),

src/gallium/drivers/panfrost/pan_job.h

@@ -79,16 +79,6 @@ pan_tristate_get(struct pan_tristate state)
         return (state.v == PAN_TRISTATE_TRUE);
 }
 
-/*
- * Check whether a tristate has a defined value (not PAN_TRISTATE_DONTCARE). If
- * true, pan_tristate_get will return a defined value.
- */
-static inline bool
-pan_tristate_is_defined(struct pan_tristate state)
-{
-        return (state.v != PAN_TRISTATE_DONTCARE);
-}
-
 /* A panfrost_batch corresponds to a bound FBO we're rendering to,
  * collecting over multiple draws. */