https://github.com/facebook/react/blob/49af88991c3a3e79e663e495458fad12d3162894/packages/react-devtools-shared/src/utils.js#L491

We have SuspenseList for the tree view but not when printing JSX.

When we fallthrough here we call getDisplayName with a symbol, because we assume that if it's not a string, then it's a function. We should be checking whether it is a function before calling getDisplayName.

Subsequently if we call getDisplayName with a symbol we get the error `invalid value used as weak map key` which messes up things after that. I think that's the actual cause of https://github.com/facebook/react/pull/19364
**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 *
import LRU from 'lru-cache';
import {
  isElement,
  typeOf,
  ContextConsumer,
  ContextProvider,
  ForwardRef,
  Fragment,
  Lazy,
  Memo,