Follow up from https://github.com/facebook/react/pull/11616.

Here's one I found. These two invariants:

https://github.com/facebook/react/blob/7e7127387ba64f57299eaff8656542cea6fb3a2d/packages/react-reconciler/src/ReactFiberClassComponent.js#L330-L343

are in a function that's behind a DEV block:

https://github.com/facebook/react/blob/7e7127387ba64f57299eaff8656542cea6fb3a2d/packages/react-reconciler/src/ReactFiberClassComponent.js#L447-L449

I don't think this is intentional, but need to verify.

There may be more. I'll use this issue to track while https://github.com/facebook/react/pull/11616 preserves existing behavior.
'%s has a method called shouldComponentUpdate(). ' +
            'shouldComponentUpdate should not be used when extending React.PureComponent. ' +
            'Please extend React.Component if shouldComponentUpdate is used.',
          getComponentName(workInProgress) || 'A pure component',
        );
      }
      const noComponentDidUnmount =
        typeof instance.componentDidUnmount !== 'function';
      warning(
        noComponentDidUnmount,
        '%s has a method called ' +
          'componentDidUnmount(). But there is no such lifecycle method. ' +
          'Did you mean componentWillUnmount()?',
        name,
      );
      const noComponentDidReceiveProps =
        typeof instance.componentDidReceiveProps !== 'function';
      warning(
        noComponentDidReceiveProps,
        '%s has a method called ' +
          'componentDidReceiveProps(). But there is no such lifecycle method. ' +
          'If you meant to update the state in response to changing props, ' +
          'use componentWillReceiveProps(). If you meant to fetch data or ' +
          'run side-effects or mutations after React has updated the UI, use componentDidUpdate().',
        name,
      );
      const noComponentWillRecieveProps =
        typeof instance.componentWillRecieveProps !== 'function';
      warning(
        noComponentWillRecieveProps,