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.
getName() {
    return this.props.name;
  }
  render() {
    attachedListener = this.props.onClick;
    renderedName = this.props.name;
    return React.createElement('div', { className: this.props.name });
  }
}
function test(element, expectedTag, expectedClassName) {
  var instance = ReactDOM.render(element, container);
  expect(container.firstChild).not.toBeNull();
  expect(container.firstChild.tagName).toBe(expectedTag);
  expect(container.firstChild.className).toBe(expectedClassName);
  return instance;
}
class Empty extends React.Component { }