title: autoGenerateWrapperClass is null react-native
body: <p>I am writing wrapper for react-native in scala-js</p>
  
  <pre><code>  lazy val reactNative = js.Dynamic.global.require("react-native")
    val View = reactNative.View
    val component = ReactNativeB[Unit]("NativeYeah")
            .render(P =&gt; {
               reactNative.createElement(View,null)
          }).buildU
    reactNative.AppRegistry.registerComponent("iOSscala", () =&gt; component())
  </code></pre>
  
  <p><strong>Component registered fine</strong> ,but its failing while creating View element! </p>
  
  <blockquote>
    <p>null is not a function (evaluating 'autoGenerateWrapperClass(tag)')"</p>
  </blockquote>
  
  <p>Full stack trace : </p>
  
  <pre><code>CTJSLog&gt; "Error: 
   stack: 
    getComponentClassForElement     index.ios.bundle:5894
    validatePropTypes               index.ios.bundle:5634
    createElement                   index.ios.bundle:5681
    renderApplication               index.ios.bundle:33913
    run                             index.ios.bundle:33858
    runApplication                  index.ios.bundle:33880
    jsCall                          index.ios.bundle:7237
    _callFunction                   index.ios.bundle:7484
    applyWithGuard                  index.ios.bundle:877
    guardReturn                     index.ios.bundle:7286
    callFunctionReturnFlushedQueue  index.ios.bundle:7493
   URL: http://localhost:8081/index.ios.bundle
   line: 5894
   message: null is not a function (evaluating 'autoGenerateWrapperClass(tag)')"
  </code></pre>
  
  <p>while debugging this function </p>
  
  <pre><code>function getComponentClassForElement(element) {
    if (typeof element.type === 'function') {
      return element.type;
    }
    var tag = element.type;
    var componentClass = tagToComponentClass[tag];
    if (componentClass == null) {
      tagToComponentClass[tag] = componentClass = autoGenerateWrapperClass(tag);
    }
    return componentClass;
  }
  </code></pre>
  
  <p>tag value is ReactElement </p>
  
  <p>Note : the above code works fine in reactjs with div tag / react component.</p>
  
  <p><strong>Edit : Its issue from scalajs-react builder ,which obeys ReactJS render API not AppRegistry , closing issue.</strong></p>