title: Bundle.classNamed(_ className: String) fails but NSClassFromString() work
body: <p>I'm working on a proof of concept of loading plugin from a host application in Swift. I'm able to load a framework or a bundle on a Bundle class, <code>NSClassFromString</code> and <code>Bundle.principalClass</code> seems to work fine, but I'm not able to get any result from <code>Bundle.classNamed</code> function.</p>
  
  <p>This is the piece of code I'm using:</p>
  
  <pre class="lang-swift prettyprint-override"><code>for fullName in bundles {
      print("Loading framework: \(fullName)")
  
      if let bundle = Bundle(path: fullName), bundle.load(),
          let name = fullName.split(separator: ".").first {
  
          let typeNamed = bundle.classNamed(name + ".Plugin") as? NSObject.Type
          let typeNS = NSClassFromString(name + ".Plugin") as? NSObject.Type
          let typeNamedV2 = bundle.classNamed(name + ".PluginV2") as? NSObject.Type
          let typeNSV2 = NSClassFromString(name + ".PluginV2") as? NSObject.Type
          let typePrincipal = bundle.principalClass as? NSObject.Type
  
          print("From bundle.classNamed: \(initPlugin(from: typeNamed)?.description ?? "")" )
          print("From NSClassFromString: \(initPlugin(from: typeNS)?.description ?? "")" )
  
          print("From bundle.classNamed: \(initPlugin(from: typeNamedV2)?.description ?? "")" )
          print("From NSClassFromString: \(initPlugin(from: typeNSV2)?.description ?? "")" )
  
          print("From bundle.principalClass: \(initPlugin(from: typePrincipal)?.description ?? "")" )
  
          bundle.unload()
      }
  }
  </code></pre>
  
  <p>The following is the output:</p>
  
  <pre><code>Loading framework: One.framework
  From bundle.classNamed: 
  From NSClassFromString: &lt;One.Plugin: 0x102802060&gt;
  From bundle.classNamed: 
  From NSClassFromString: &lt;One.PluginV2: 0x102802060&gt;
  From bundle.principalClass: &lt;One.Plugin: 0x102801650&gt;
  Loading framework: CommonInterface.framework
  From bundle.classNamed: 
  From NSClassFromString: 
  From bundle.classNamed: 
  From NSClassFromString: 
  From bundle.principalClass: 
  Loading framework: Bundle.bundle
  From bundle.classNamed: 
  From NSClassFromString: &lt;Bundle.Plugin: 0x102b08040&gt;
  From bundle.classNamed: 
  From NSClassFromString: &lt;Bundle.PluginV2: 0x102b08f80&gt;
  From bundle.principalClass: &lt;Bundle.Plugin: 0x102801ea0&gt;
  </code></pre>
  
  <p>Project is configured for Swift 5 and Xcode 11 building.</p>
  
  <p>Here you can find the complete source code of the POC: </p>
  
  <p><a href="https://github.com/lechuckcaptain/SwiftPluginArchitectureExample" rel="nofollow noreferrer">https://github.com/lechuckcaptain/SwiftPluginArchitectureExample</a></p>
  
  <p>Any hint/feedback are welcome!</p>