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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

return (
          <Suspense fallback={<Text text="Loading..." />}>
            <AsyncTextWithUnmount text={text} ms={100} />
          </Suspense>
        );
      }
      const root = ReactTestRenderer.create(<App text="A" />);
      expect(ReactTestRenderer).toHaveYielded(['Suspend! [A]', 'Loading...']);
      root.update(<Text text="B" />);
      
      expect(ReactTestRenderer).toHaveYielded(['B']);
      expect(root).toMatchRenderedOutput('B');
    });
    it('suspends in a component that also contains useEffect', () => {
      const {useLayoutEffect} = React;
      function AsyncTextWithEffect(props) {