title: conformsToProtocol will not compile with custom Protocol
body: <p>I want to check that a <code>UIViewController</code> conforms to a protocol of my own creation: </p>
  
  <pre><code>import UIKit
  
  protocol myProtocol {
      func myfunc()
  }
  
  class vc : UIViewController {
  
  }
  
  extension vc : myProtocol {
      func myfunc() {
          //My implementation for this class
      }
  }
  
  //Not allowed
  let result = vc.conformsToProtocol(myProtocol)
  
  //Allowed
  let appleResult = vc.conformsToProtocol(UITableViewDelegate)
  </code></pre>
  
  <p>However I get the following error :</p>
  
  <p><code>Cannot convert value of type '(myprotocol).Protocol' (aka 'myprotocol.Protocol') to expected argument type 'Protocol'</code></p>
  
  <p><a href="https://i.stack.imgur.com/d299G.png" rel="noreferrer"><img src="https://i.stack.imgur.com/d299G.png" alt="Playground"></a></p>
  
  <p>What am I doing wrong?</p>