With this:

```js
    const Add = React.memo(props => {
      return props.inner + props.outer;
    });
    Add.defaultProps = {
      inner: 2,
    };
    const LazyAdd = lazy(() => fakeImport(Add));
```

If I render `LazyAdd` again after it resolves, it won't get the `inner` default prop value. This is a bug.
if (Component) {
    warningWithoutStack(
      !Component.childContextTypes,
      '%s(...): childContextTypes cannot be defined on a function component.',
      Component.displayName || Component.name || 'Component',
    );
  }
  if (workInProgress.ref !== null) {
    let info = '';
    const ownerName = getCurrentFiberOwnerNameInDevOrNull();
    if (ownerName) {
      info += '\n\nCheck the render method of `' + ownerName + '`.';
    }
    let warningKey = ownerName || workInProgress._debugID || '';
    const debugSource = workInProgress._debugSource;
    if (debugSource) {
      warningKey = debugSource.fileName + ':' + debugSource.lineNumber;
    }
    if (!didWarnAboutFunctionRefs[warningKey]) {
      didWarnAboutFunctionRefs[warningKey] = true;
      warning(
        false,
        'Function components cannot be given refs. ' +
          'Attempts to access this ref will fail.%s',
        info,