**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
Page load throws console error: `Warning: Stateless function components cannot be given refs. Attempts to access this ref will fail.null`

```
// Chrome console
6VM598:27 Warning: Stateless function components cannot be given refs. Attempts to access this ref will fail.null
window.console.error @ VM598:27
printWarning @ warning.js:36
warning @ warning.js:60
mountIndeterminateComponent @ react-dom.development.js:10488
beginWork @ react-dom.development.js:10647
performUnitOfWork @ react-dom.development.js:12621
workLoop @ react-dom.development.js:12730
callCallback @ react-dom.development.js:1319
invokeGuardedCallbackDev @ react-dom.development.js:1358
invokeGuardedCallback @ react-dom.development.js:1215
performWork @ react-dom.development.js:12848
batchedUpdates @ react-dom.development.js:13292
performFiberBatchedUpdates @ react-dom.development.js:1666
stackBatchedUpdates @ react-dom.development.js:1657
batchedUpdates @ react-dom.development.js:1671
batchedUpdatesWithControlledComponents @ react-dom.development.js:1684
dispatchEvent @ react-dom.development.js:1894
```

**What is the expected behavior?**
No console error. Or at least some way to trace which is the stateless component that is causing the issue.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
`"react": "^16.0.0-rc.3",`
`Chrome Version 60.0.3112.113 (Official Build) (64-bit)`
`macOS Sierra 10.12.6`


- This error only started to appear after upgrading from React 15 -> 16.
const NESTED_UPDATE_LIMIT = 1000;
  let nestedUpdateCount: number = 0;
  let nextRenderedTree: FiberRoot | null = null;
  function resetContextStack() {
    
    reset();
    
    resetContext();
    resetHostContainer();
  }
   resetNextUnitOfWork mutates the current priority context. It is reset after
   after the workLoop exits, so never call resetNextUnitOfWork from outside
   the work loop.
  function resetNextUnitOfWork() {
    
    while (
      nextScheduledRoot !== null &&
      nextScheduledRoot.current.pendingWorkPriority === NoWork
    ) {
      
      nextScheduledRoot.isScheduled = false;
      
      
      const next = nextScheduledRoot.nextScheduledRoot;
      nextScheduledRoot.nextScheduledRoot = null;
      
      if (nextScheduledRoot === lastScheduledRoot) {
        nextScheduledRoot = null;
        lastScheduledRoot = null;
        nextPriorityLevel = NoWork;