gallium: add draw_stage::destroy().
diff --git a/src/mesa/pipe/draw/draw_private.h b/src/mesa/pipe/draw/draw_private.h
index 53d7451..ca5ca7b 100644
--- a/src/mesa/pipe/draw/draw_private.h
+++ b/src/mesa/pipe/draw/draw_private.h
@@ -124,6 +124,8 @@
    void (*reset_tmps)( struct draw_stage * );
 
    void (*reset_stipple_counter)( struct draw_stage * );
+
+   void (*destroy)( struct draw_stage * );
 };