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**Do you want to request a *feature* or report a *bug*?**
bug, I believe, unless I misunderstand how it works
**What is the current behavior?**
Given a `Suspense` inside `Suspense` case like
```
<Suspense fallback="Fallback 1">
  <LazyText1 text="First text" />
  <Suspense fallback="Fallback 2">
    <LazyText2 text="Second text!" />
  </Suspense>
</Suspense>
```

Promises in `LazyTexts` start resolving at the same time, but if `LazyText2` is resolved first it never renders, `Fallback 2` stays.

Result:
```
First text

Fallback 2
```

Please see https://codesandbox.io/s/234o4zry7n

**What is the expected behavior?**

Every `LazyText` displayed in the end
```
First text

Second text!
```

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
react, react-dom 16.6.0

let wrapped;
      const Component = jest.fn(() => {
        wrapped = SchedulerTracing.unstable_wrap(callback);
        return null;
      });
      let interaction;
      SchedulerTracing.unstable_trace('event', mockNow(), () => {
        const interactions = SchedulerTracing.unstable_getCurrent();
        expect(interactions.size).toBe(1);
        interaction = Array.from(interactions)[0];
        ReactTestRenderer.create(<Component />);
      });
      expect(Component).toHaveBeenCalledTimes(1);
      expect(onInteractionScheduledWorkCompleted).not.toHaveBeenCalled();
      expect(callback).not.toHaveBeenCalled();
      wrapped();
      expect(callback).toHaveBeenCalledTimes(1);
      expect(onInteractionScheduledWorkCompleted).toHaveBeenCalledTimes(1);
      expect(
        onInteractionScheduledWorkCompleted,
      ).toHaveBeenLastNotifiedOfInteraction(interaction);
    });
    it('should associate traced events with their subsequent commits', () => {
      let instance = null;
      const Yield = ({duration = 10, value}) => {
        advanceTimeBy(duration);
        ReactTestRenderer.unstable_yield(value);
        return null;
      };
      class Example extends React.Component {