**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.
workInProgress.tag = CoroutineHandlerPhase;
    
    
    var yields: Array<mixed> = [];
    appendAllYields(yields, workInProgress);
    var fn = coroutine.handler;
    var props = coroutine.props;
    var nextChildren = fn(props, yields);
    var currentFirstChild = current !== null ? current.child : null;
    // Inherit the priority of the returnFiber.
    const priority = workInProgress.pendingWorkPriority;
    workInProgress.child = reconcileChildFibers(
      workInProgress,
      currentFirstChild,
      nextChildren,
      priority,
    );
    return workInProgress.child;
  }
  function appendAllChildren(parent: I, workInProgress: Fiber) {
    
    
    let node = workInProgress.child;
    while (node !== null) {
      if (node.tag === HostComponent || node.tag === HostText) {
        appendInitialChild(parent, node.stateNode);
      } else if (node.tag === HostPortal) {