We don't actually use this anywhere, so let's remove it.

https://github.com/facebook/react/blob/f1d00156df5453bc62bd5668fefdcac4ca67e90e/src/renderers/shared/fiber/ReactFiberScheduler.js#L1504-L1512
element.type.prototype != null &&
      (element.type.prototype: any).unstable_isAsyncReactComponent === true;
    const priorityLevel = getPriorityContext(current, forceAsync);
    const nextState = {element};
    callback = callback === undefined ? null : callback;
    if (__DEV__) {
      warning(
        callback === null || typeof callback === 'function',
        'render(...): Expected the last optional `callback` argument to be a ' +
          'function. Instead received: %s.',
        callback,
      );
    }
    addTopLevelUpdate(current, nextState, callback, priorityLevel);
    scheduleUpdate(current, priorityLevel);
  }
  return {
    createContainer(containerInfo: C): OpaqueRoot {
      return createFiberRoot(containerInfo);
    },
    updateContainer(
      element: ReactNodeList,
      container: OpaqueRoot,
      parentComponent: ?React$Component<any, any>,
      callback: ?Function,
    ): void {
      
      const current = container.current;
      if (__DEV__) {
        if (ReactFiberInstrumentation.debugTool) {