**What is the current behavior?**

TypeError: Do not know how to serialize a BigInt which makes it so the react dev tools cannot inspect the component props.

Steps to reproduce

1. Set a component prop to some value of type `BigInt`.
2. Open Chrome DevTools, then React Components view, try inspecting the component
3. There will be an exception [here](https://github.com/facebook/react/blob/b438699d3620bff236282b049204e1221b3689e9/packages/react-devtools-extensions/src/contentScript.js#L28-L38) (with the message above)

You can repro this with the following https://codesandbox.io/s/mystifying-cache-jshv3

Note that you need to repo via Chrome DevTools so that the bridge is active, if you use the codesandbox built-in DevTools the behavior is different.

**What is the expected behavior?**

That bigints are handled in a similar way to how symbols are handled. So that they don't crash when they cross a boundary, i.e. postMessage.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

Latest version, hasn't worked before. That I know. Tested in Chrome and Firefox, although the behavior isn't exactly the same in Firefox as in Chrome, it doesn't appear to work in Firefox either.

I would like to propose a fix for this but I cannot find where in the source this would go. I don't care for editing capabilities and such, I just don't want the dev tools to give up on my just because I have BigInts in my code.

case 'symbol':
      return 'symbol';
    default:
      return 'unknown';
  }
}
/**
 * Generate the dehydrated metadata for complex object instances
 */
function createDehydrated(
  type: string,
  inspectable: boolean,
  data: Object,
  cleaned: Array<Array<string | number>>,
  path: Array<string | number>,
): Dehydrated {
  cleaned.push(path);
  const dehydrated: Dehydrated = {
    inspectable,
    type,
    name:
      !data.constructor || data.constructor.name === 'Object'
        ? ''
        : data.constructor.name,
  };
  if (type === 'array' || type === 'typed_array') {
    dehydrated.size = data.length;
  } else if (type === 'object') {
    dehydrated.size = Object.keys(data).length;
  }