Given the following test case

``` jsx
function TestCmp() {
  return <span>{NaN}</span>;
}

ReactDOM.render(<TestCmp />, document.getElementById('app'));
```

Produces the following warning:

```
Warning: Component's children should not be mutated.
    in span (created by TestCmp)
    in TestCmp (created by Unknown)
```

This is probably caused by [this mutation check](https://github.com/facebook/react/blob/328fc75bc910032ff37dc9d93429fb14b476bd0d/src/renderers/shared/hooks/ReactChildrenMutationWarningHook.js#L34), which was introduced in 15.3.0, but it doesn't work for NaN, because NaN != NaN

render() {
          return <div><Child name="child" /></div>;
        }
      }
      class Child extends React.Component {
        render() {
          return <span>My name is {this.props.name}</span>;
        }
      }
      var response = ReactServerRendering.renderToString(
        <Parent />
      );
      expect(response).toMatch(new RegExp(
        '<div ' + ROOT_ATTRIBUTE_NAME + '="" ' +
          ID_ATTRIBUTE_NAME + '="[^"]+" ' +
          ReactMarkupChecksum.CHECKSUM_ATTR_NAME + '="[^"]+">' +
          '<span ' + ID_ATTRIBUTE_NAME + '="[^"]+">' +
            '<!-- react-text: [0-9]+ -->My name is <!-- /react-text -->' +
            '<!-- react-text: [0-9]+ -->child<!-- /react-text -->' +
          '</span>' +
        '</div>'
      ));
    });
    it('should only execute certain lifecycle methods', () => {
      function runTest() {
        var lifecycle = [];
        class TestComponent extends React.Component {