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

bug

**What is the current behavior?**

With React 16.3.0, when using `<React.Fragment>` IE 11 gives the following warning:

```
Warning: Invalid prop `children` supplied to `React.Fragment`. React.Fragment can only have `key` and `children` props.
```

Steps to reproduce:
1. Use `create-react-app` to create a new React app.
2. Add `<React.Fragment>` to `App.js`. For example:

```
import React, { Component } from "react";
import logo from "./logo.svg";
import "./App.css";

class App extends Component {
  render() {
    return (
      <div className="App">
        <React.Fragment>
          <header className="App-header">
            <img src={logo} className="App-logo" alt="logo" />
            <h1 className="App-title">Welcome to React</h1>
          </header>
          <p className="App-intro">
            To get started, edit <code>src/App.js</code> and save to reload.
          </p>
        </React.Fragment>
      </div>
    );
  }
}

export default App;
```

3. Open the app in IE 11.
4. Open IE dev tools and refresh the browser.
5. You should see the above mentioned warning message in the console window.

No warnings with Chrome, Firefox, and Edge.

**What is the expected behavior?**

There should be no warnings shown.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

React: 16.3.0
Browser: IE 11
OS: Windows 10
let info = getDeclarationErrorAddendum();
  if (!info) {
    const parentName =
      typeof parentType === 'string'
        ? parentType
        : parentType.displayName || parentType.name;
    if (parentName) {
      info = `\n\nCheck the top-level render call using <${parentName}>.`;
    }
  }
  return info;
}
/**
 * Warn if the element doesn't have an explicit key assigned to it.
 * This element is in an array. The array could grow and shrink or be
 * reordered. All children that haven't already been validated are required to
 * have a "key" property assigned to it. Error statuses are cached so a warning
 * will only be shown once.
 *
 * @internal
 * @param {ReactElement} element Element that requires a key.
 * @param {*} parentType element's parent's type.
 */
function validateExplicitKey(element, parentType) {