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

**What is the current behavior?**
App doesn't render in IE11 and below.

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).**
- Build React app with Webpack
- Launch IE11 or below (not an emulator)
- You will see a blank screen or half-compiled React app with the following error:
![24f8f6e8-afde-11e6-9a6f-a3cc6355f55c](https://cloud.githubusercontent.com/assets/1647596/20527736/7b9075a8-b097-11e6-8ccb-d205b1908f31.png)

**What is the expected behavior?**
- To render as it does in Chrome, Firefox, etc.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
We've temporarily shrink-wrapped our dependencies so that we can continue to serve our app. We're starting to believe that it's coming from a dependency that `react`, `apollo`  or `webpack` may be relying on...

Shrink-wrapped versions of our dependencies (left is the new one that's broken and the right one is the old one that continues to work across all browsers) https://www.diffchecker.com/SyaJUcsk
var componentClass = element.type;
  if (typeof componentClass !== 'function') {
    return;
  }
  var name = componentClass.displayName || componentClass.name;
  var propTypes = componentClass.propTypes;
  if (propTypes) {
    currentlyValidatingElement = element;
    checkPropTypes(propTypes, element.props, 'prop', name, getStackAddendum);
    currentlyValidatingElement = null;
  }
  if (typeof componentClass.getDefaultProps === 'function') {
    warning(
      componentClass.getDefaultProps.isReactClassApproved,
      'getDefaultProps is only used on classic React.createClass ' +
        'definitions. Use a static property named `defaultProps` instead.',
    );
  }
}
/**
 * Given a fragment, validate that it can only be provided with fragment props
 * @param {ReactElement} fragment
 */
function validateFragmentProps(fragment) {