**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.
/**
 * Copyright (c) 2013-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @providesModule ReactFiberBeginWork
 * @flow
 */
'use strict';
import type {ReactCoroutine} from 'ReactTypes';
import type {Fiber} from 'ReactFiber';
import type {HostContext} from 'ReactFiberHostContext';
import type {HydrationContext} from 'ReactFiberHydrationContext';
import type {FiberRoot} from 'ReactFiberRoot';
import type {HostConfig} from 'ReactFiberReconciler';
import type {PriorityLevel} from 'ReactPriorityLevel';
var {
  mountChildFibersInPlace,
  reconcileChildFibers,
  reconcileChildFibersInPlace,
  cloneChildFibers,
} = require('ReactChildFiber');
var {beginUpdateQueue} = require('ReactFiberUpdateQueue');