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.
await ReactNoop.act(async () => {
      transitionToPage('C');
      
      
      Scheduler.unstable_advanceTime(600);
      await advanceTimers(600);
      expect(Scheduler).toFlushAndYield(['B', 'L', 'C']);
      
      
      
      expect(ReactNoop.getChildren()).toEqual([span('B'), span('L')]);
      Scheduler.unstable_advanceTime(400);
      await advanceTimers(400);
      expect(ReactNoop.getChildren()).toEqual([span('C')]);
    });
    await ReactNoop.act(async () => {
      transitionToPage('D');
      
      
      Scheduler.unstable_advanceTime(1000);
      await advanceTimers(1000);
      expect(Scheduler).toFlushAndYield(['C', 'L', 'D']);
      
      
      expect(ReactNoop.getChildren()).toEqual([span('D')]);
    });
  });
  it("suspended commit remains suspended even if there's another update at same expiration", async () => {
    
    function App({text}) {