React version: 18.3.0-next-3ba7add60-20221201

Hard to reproduce.

In Next.js, in rare cases, and only after a fast refresh, the ref object when using forwardRef is simply `{}`.

This leads to the `TypeError: can't define property "current": Object is not extensible` error when used with `useImperativeHandle`.

```tsx
function Parent() {
  const carouselRef = useRef<any>();

  return <Suspense><Carousel ref={carouselRef} /></Suspense>
}

const Carousel = forwardRef((props, ref) => {
  if (!('current' in ref)) { debugger; }
  const thing = use(aPromise);
  return ...;
});
```

![Screenshot 2023-03-17 at 18 49 21](https://user-images.githubusercontent.com/5406212/225981809-22f575fa-0ec7-4f94-ae23-bffc8bf7c4dd.png)

In `updateImperativeHandle`, the ref is already an empty object.

![Screenshot 2023-03-17 at 19 13 13](https://user-images.githubusercontent.com/5406212/225985622-b8512a61-3a6b-4958-b63f-277219d4c816.png)

I haven't investigated it further yet, the stacktraces are quite hard to follow.
ensureRootIsScheduled(root);
    throw fatalError;
  }
  if (exitStatus === RootDidNotComplete) {
     
     
     
    markRootSuspended(root, lanes);
    ensureRootIsScheduled(root);
    return null;
  }
   We now have a consistent tree. Because this is a sync render, we
   will commit it even if something suspended.
  const finishedWork: Fiber = (root.current.alternate: any);
  root.finishedWork = finishedWork;
  root.finishedLanes = lanes;
  commitRoot(
    root,
    workInProgressRootRecoverableErrors,
    workInProgressTransitions,
  );
   Before exiting, make sure there's a callback scheduled for the next
   pending level.
  ensureRootIsScheduled(root);
  return null;
}
export function flushRoot(root: FiberRoot, lanes: Lanes) {
  if (lanes !== NoLanes) {
    markRootEntangled(root, mergeLanes(lanes, SyncLane));
    ensureRootIsScheduled(root);