freedreno/a6xx: bail instead of crash for compile fails

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5907>
diff --git a/src/gallium/drivers/freedreno/a6xx/fd6_draw.c b/src/gallium/drivers/freedreno/a6xx/fd6_draw.c
index dd9c750..810bdf0 100644
--- a/src/gallium/drivers/freedreno/a6xx/fd6_draw.c
+++ b/src/gallium/drivers/freedreno/a6xx/fd6_draw.c
@@ -178,10 +178,16 @@
 		.primitive_restart = info->primitive_restart && info->index_size,
 	};
 
+	if (!(ctx->prog.vs && ctx->prog.fs))
+		return false;
+
 	if (info->mode == PIPE_PRIM_PATCHES) {
 		emit.key.hs = ctx->prog.hs;
 		emit.key.ds = ctx->prog.ds;
 
+		if (!(ctx->prog.hs && ctx->prog.ds))
+			return false;
+
 		shader_info *ds_info = &emit.key.ds->nir->info;
 		emit.key.key.tessellation = ir3_tess_mode(ds_info->tess.primitive_mode);
 	}