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.
/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @emails react-core
 */
'use strict';
let ExecutionEnvironment;
let PropTypes;
let React;
let ReactDOM;
let ReactDOMServer;
let ReactTestUtils;
const stream = require('stream');
const TEXT_NODE_TYPE = 3;
function asyncReactDOMRender(reactElement, domElement, forceHydrate) {
  return new Promise(resolve => {
    if (forceHydrate) {
      ReactDOM.hydrate(reactElement, domElement);
    } else {
      ReactDOM.render(reactElement, domElement);
    }
    
    
    resolve();
  });
}
async function expectErrors(fn, count) {