While implementing bug 1607560 I noticed that for both the Symbol and BigInt wrong data is returned.

Chrome:

>>> var result = Runtime.evaluate({ expression: "42n"});
>>> result
Promise {
  {
    result: { type: 'bigint', unserializableValue: '42n', description: '42n' }
  },
  inspect: [AsyncFunction]
}
>>> var result = Runtime.evaluate({ expression: "42n", returnByValue: false});
>>> result
Promise {
  {
    result: { type: 'bigint', unserializableValue: '42n', description: '42n' }
  },
  inspect: [AsyncFunction]
}

Firefox:

>>> var result = Runtime.evaluate({ expression: "42n"});
>>> result
Promise {
  {
    result: {
      objectId: 'c8843032-e079-7342-83ee-2814d2f17970',
      type: 'bigint'
    }
  },
  inspect: [AsyncFunction]
}
>>> var result = Runtime.evaluate({ expression: "42n", returnByValue: false});
>>> result
Promise {
  {
    result: {
      objectId: '2ff2b537-d5de-414e-b783-7290981217ca',
      type: 'bigint'
    }
  },
  inspect: [AsyncFunction]
}

It would be great to see that fixed, which would simplify the changes on bug 1607560.

This actually also affects Runtime.callFunctionOn.

Depends on D67842

https://hg.mozilla.org/mozilla-central/rev/9f72cf155767