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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

expect(root).toMatchRenderedOutput('Hi');
  });
  it('throws if tree suspends and none of the Suspense ancestors have a fallback', () => {
    const root = ReactTestRenderer.create(
      <Suspense>
        <AsyncText text="Hi" ms={1000} />
      </Suspense>,
      {
        unstable_isConcurrent: true,
      },
    );
    let err;
    try {
      root.unstable_flushAll();
    } catch (e) {
      err = e;
    }
    expect(err.message.replace(/at .+?:\d+/g, 'at **')).toBe(
      'AsyncText suspended while rendering, but no fallback UI was specified.\n' +
        '\n' +
        'Add a <Suspense fallback=...> component higher in the tree to provide ' +
        'a loading indicator or placeholder to display.\n' +
        (__DEV__ ? '    in AsyncText (at **)\n' : '    in AsyncText\n') +
        (__DEV__ ? '    in Suspense (at **)' : '    in Suspense'),
    );
    expect(ReactTestRenderer).toHaveYielded(['Suspend! [Hi]', 'Suspend! [Hi]']);
  });
  describe('outside concurrent mode', () => {
    it('a mounted class component can suspend without losing state', () => {
      class TextWithLifecycle extends React.Component {