title: Portable Class Library Profile 78 missing attribute related methods/properties
body: <p>In my PCL core project (WP8, Android, iOS, Xamarin, MvvmCross) I use custom attributes. The  Type.GetCustomAttributes() extension method lets me examine the attributes used.</p>
  
  <p>Using PCL Profile104 this works well. But because I want to use async/await, I'll need to use PCL Profile78 (and .NET 4.5)</p>
  
  <p>Problem: Seems the GetCustomAttributes() and the Attributes property are not available in Profile78. Why??</p>
  
  <p>Note:
  I am looking into the workaround by creating a PCL Profile 104 class library and wrapping the GetCustomAttributes() and then referencing this library from my PCL Profile78 library. However it seems extensionmethods are not supported... </p>
  
  <p>Example Code:</p>
  
  <pre><code>public Pcl78Class()
  {
      Type t = this.GetType();
      var attributes = t.Attributes;
      var customAttributes = t.GetCustomAttributes(true);
  
      // another weird thing: Why is VS CodeCompletion telling me it knows CustomAttributeExtensions class and methods?
      //System.Reflection.CustomAttributeExtensions.GetCustomAttributes(t);
  }
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/ekuBL.png" alt="enter image description here"></p>