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.
progressedChild.return = primaryChildFragment;
          progressedChild = progressedChild.sibling;
        }
      }
      const fallbackChildFragment = createFiberFromFragment(
        nextFallbackChildren,
        mode,
        renderExpirationTime,
        null,
      );
      fallbackChildFragment.return = workInProgress;
      primaryChildFragment.sibling = fallbackChildFragment;
       
       
      workInProgress.memoizedState = mountSuspenseState(renderExpirationTime);
      workInProgress.child = primaryChildFragment;
      return fallbackChildFragment;
    } else {
       
      const nextPrimaryChildren = nextProps.children;
      workInProgress.memoizedState = null;
      return (workInProgress.child = mountChildFibers(
        workInProgress,
        null,
        nextPrimaryChildren,
        renderExpirationTime,
      ));
    }
  } else {