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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

state = {
            hasMounted: false,
          };
          componentDidMount() {
            wrappedCascadingFn = SchedulerTracing.unstable_wrap(() => {
              this.setState({hasMounted: true});
            });
          }
          render() {
            const {ms, text} = this.props;
            TextResource.read([text, ms]);
            return <span prop={text}>{this.state.hasMounted}</span>;
          }
        }
        const interaction = {
          id: 0,
          name: 'initial render',
          timestamp: mockNow(),
        };
        const onRender = jest.fn();
        SchedulerTracing.unstable_trace(
          interaction.name,
          interaction.timestamp,
          () => {
            ReactTestRenderer.create(
              <React.unstable_Profiler id="app" onRender={onRender}>
                <React.Suspense
                  maxDuration={1000}
                  fallback={<Text text="loading" />}>