Repro: https://codesandbox.io/s/fast-water-4i4jb

Notice the flash. I'd expect `suspended` to be `true` during the high pri render.
in fallback state. Then we render each row in the  one-by-one.
 That happens in the completeWork phase without going back to beginWork.
function updateSuspenseListComponent(
  current: Fiber | null,
  workInProgress: Fiber,
  renderExpirationTime: ExpirationTime,
) {
  const nextProps = workInProgress.pendingProps;
  const revealOrder: SuspenseListRevealOrder = nextProps.revealOrder;
  const Mode: SuspenseListTailMode = nextProps.;
  const newChildren = nextProps.children;
  validateRevealOrder(revealOrder);
  validateTailOptions(Mode, revealOrder);
  validateSuspenseListChildren(newChildren, revealOrder);
  reconcileChildren(current, workInProgress, newChildren, renderExpirationTime);
  let suspenseContext: SuspenseContext = suspenseStackCursor.current;
  let shouldForceFallback = hasSuspenseContext(
    suspenseContext,
    (ForceSuspenseFallback: SuspenseContext),
  );
  if (shouldForceFallback) {
    suspenseContext = setShallowSuspenseContext(
      suspenseContext,
      ForceSuspenseFallback,
    );
    workInProgress.effectTag |= DidCapture;
  } else {
    const didSuspendBefore =
      current !== null && (current.effectTag & DidCapture) !== NoEffect;
    if (didSuspendBefore) {