Currently, if you define `shouldComponentUpdate` on `React.PureComponent` nothing bad happens and it acts like `React.Component` https://jsfiddle.net/jekmdfva/

We should probably warn in dev since it defaults the point of `PureComponent`
}
    }
    
    const updateQueue = workInProgress.updateQueue;
    const oldState = workInProgress.memoizedState;
    
    let newState;
    if (updateQueue !== null) {
      newState = beginUpdateQueue(
        workInProgress,
        updateQueue,
        instance,
        oldState,
        newProps,
        priorityLevel,
      );
    } else {
      newState = oldState;
    }
    if (
      oldProps === newProps &&
      oldState === newState &&
      !hasContextChanged() &&
      !(updateQueue !== null && updateQueue.hasForceUpdate)
    ) {
      
      
      if (typeof instance.componentDidUpdate === 'function') {
        if (
          oldProps !== current.memoizedProps ||