Improve iteration in MakeIterator

src/utils/itertools.ts

@@ -11,14 +11,14 @@ export function * MakeIterator(root: IContainerModel): Generator<IContainerModel
 
     yield container;
 
-    // if this reverse() gets costly, replace it by a simple for
-    container.children.forEach((child) => {
+    for (let i = container.children.length - 1; i >= 0; i--) {
+      const child = container.children[i];
       if (visited.has(child)) {
         return;
       }
       visited.add(child);
       queue.push(child);
-    });
+    }
   }
 }