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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

onWorkCanceled = jest.fn();
      onWorkScheduled = jest.fn(() => {
        if (throwInOnWorkScheduled) {
          throw Error('Expected error onWorkScheduled');
        }
      });
      onWorkStarted = jest.fn(() => {
        if (throwInOnWorkStarted) {
          throw Error('Expected error onWorkStarted');
        }
      });
      onWorkStopped = jest.fn(() => {
        if (throwInOnWorkStopped) {
          throw Error('Expected error onWorkStopped');
        }
      });
      
      SchedulerTracing.unstable_subscribe({
        onInteractionScheduledWorkCompleted,
        onInteractionTraced,
        onWorkCanceled,
        onWorkScheduled,
        onWorkStarted,
        onWorkStopped,
      });
    }
    beforeEach(() => loadModulesForTracing());
    describe('error handling', () => {
      it('should cover errors thrown in onWorkScheduled', () => {
        function Component({children}) {