-fix shader param names broken issue on code completion

-fix z order issue in new 2D engine

scene/resources/material.cpp

@@ -582,7 +582,7 @@ void ShaderMaterial::get_argument_options(const StringName& p_function,int p_idx
 			List<PropertyInfo> pl;
 			shader->get_param_list(&pl);
 			for (List<PropertyInfo>::Element *E=pl.front();E;E=E->next()) {
-				r_options->push_back(E->get().name);
+				r_options->push_back("\""+E->get().name.replace("shader_param/","")+"\"");
 			}
 		}
 	}

servers/visual/visual_server_raster.cpp

@@ -6253,6 +6253,10 @@ void VisualServerRaster::_render_canvas_item(CanvasItem *p_canvas_item,const Mat
 		sorter.sort(child_items,child_item_count);
 	}
 
+	if (ci->z_relative)
+		p_z=CLAMP(p_z+ci->z,CANVAS_ITEM_Z_MIN,CANVAS_ITEM_Z_MAX);
+	else
+		p_z=ci->z;
 
 	for(int i=0;i<child_item_count;i++) {
 
@@ -6267,10 +6271,6 @@ void VisualServerRaster::_render_canvas_item(CanvasItem *p_canvas_item,const Mat
 		ci->final_transform=xform;
 		ci->final_opacity=opacity * ci->self_opacity;
 
-		if (ci->z_relative)
-			p_z=CLAMP(p_z+ci->z,CANVAS_ITEM_Z_MIN,CANVAS_ITEM_Z_MAX);
-		else
-			p_z=ci->z;
 
 		int zidx = p_z-CANVAS_ITEM_Z_MIN;