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.
Scheduler.unstable_advanceTime(10000);
      
      return <AsyncText text={text} ms={200000} />;
    }
    function App() {
      return (
        <Suspense fallback="Loading...">
          <ExpensiveText text="A" />
          <ExpensiveText text="B" />
          <ExpensiveText text="C" />
        </Suspense>
      );
    }
    ReactNoop.render(<App />);
    expect(Scheduler).toFlushAndYield([
      'Suspend! [A]',
      'Suspend! [B]',
      'Suspend! [C]',
    ]);
    expect(ReactNoop).toMatchRenderedOutput('Loading...');
    await advanceTimers(200000);
    expect(Scheduler).toHaveYielded([
      'Promise resolved [A]',
      'Promise resolved [B]',
      'Promise resolved [C]',
    ]);