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.
static contextTypes = {
    tag: PropTypes.string,
    className: PropTypes.string
  };
  state = {
    tag: this.context.tag,
    className: this.context.className
  };
  render() {
    var Tag = this.state.tag;
    return React.createElement(Tag, {className: this.state.className});
  }
}
class ProvideChildContextTypes extends React.Component {
  static childContextTypes = {
    tag: PropTypes.string,
    className: PropTypes.string
  };
  getChildContext() {
    return { tag: 'span', className: 'foo' };
  }
  render() {
    return React.createElement(StateBasedOnContext);
  }
}
var renderCount = 0;
class RenderOnce extends React.Component {