Repro case with a master build: https://codesandbox.io/s/stoic-mcnulty-dhygf?file=/src/App.js:668-703

Expected: we see content after a second.
Actual: fallback never resolves.

This happens in a sequence of:

1. Normal update
   - which suspends
2. Idle update
   - which also suspends
3. An unrelated normal update immediately followed by a ping (so they're batched)
   - here, we decide to stay on fallback, but should've shown the content

If you remove `_setVersion(v => v + 1);` on line 44 then the issue goes away.
current: Fiber | null,
  workInProgress: Fiber,
  renderExpirationTime: ExpirationTime,
): Fiber | null {
  if (current !== null) {
     
    workInProgress.dependencies = current.dependencies;
  }
  if (enableProfilerTimer) {
     
    stopProfilerTimerIfRunning(workInProgress);
  }
  const updateExpirationTime = workInProgress.expirationTime;
  if (updateExpirationTime !== NoWork) {
    markUnprocessedUpdateTime(updateExpirationTime);
  }
   Check if the children have any pending work.
  const childExpirationTime = workInProgress.childExpirationTime;
  if (childExpirationTime < renderExpirationTime) {
     
     
     
    return null;
  } else {
     
     
    cloneChildFibers(current, workInProgress);
    return workInProgress.child;
  }
}