DRW: Change Procedural function to use a GPUBatch

This is in order to have VAO handled by thoses batches instead of using a
common VAO. Even if the VAO has no importance in these case using a batch
will help when transitioning to Vulkan.

source/blender/draw/intern/draw_manager.h

@@ -152,8 +152,8 @@ typedef struct DRWCall {
       uint count;
     } instances;
     struct { /* type == DRW_CALL_PROCEDURAL */
+      GPUBatch *geometry;
       uint vert_count;
-      GPUPrimType prim_type;
     } procedural;
   };
 
@@ -438,6 +438,11 @@ void drw_debug_init(void);
 void drw_batch_cache_validate(Object *ob);
 void drw_batch_cache_generate_requested(struct Object *ob);
 
+/* Procedural Drawing */
+GPUBatch *drw_cache_procedural_points_get(void);
+GPUBatch *drw_cache_procedural_lines_get(void);
+GPUBatch *drw_cache_procedural_triangles_get(void);
+
 extern struct GPUVertFormat *g_pos_format;
 
 #endif /* __DRAW_MANAGER_H__ */