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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

workInProgress.memoizedProps = workInProgress.pendingProps;
    if (workInProgress.mode & ProfileMode) {
      // 
      stopProfilerTimerIfRunningAndRecordDelta(workInProgress, true);
    }
  } else {
    next = beginWork(current, workInProgress, nextRenderExpirationTime);
    workInProgress.memoizedProps = workInProgress.pendingProps;
  }
  if (__DEV__) {
    ReactCurrentFiber.resetCurrentFiber();
    if (isReplayingFailedUnitOfWork) {
      // 
      // 
      // 
      // 
      rethrowOriginalError();
    }
  }
  if (__DEV__ && ReactFiberInstrumentation.debugTool) {
    ReactFiberInstrumentation.debugTool.onBeginWork(workInProgress);
  }
  if (next === null) {
    // 
    next = completeUnitOfWork(workInProgress);
  }
  ReactCurrentOwner.current = null;
  return next;
}
function workLoop(isYieldy) {