Automatically generate correct marshalling for callbacks

Author: jkoritzinsky

Win32/ComStream.cs

@@ -257,7 +257,7 @@ private static Result CloneImpl(IntPtr thisPtr, out IntPtr streamPointer)
                     var shadow = ToShadow<ComStreamShadow>(thisPtr);
                     var callback = ((IStream)shadow.Callback);
                     var clone = callback.Clone();
-                    streamPointer = ComStream.ToIntPtr(clone);
+                    streamPointer = ComStreamShadow.ToIntPtr(clone);
                 }
                 catch (SharpGenException exception)
                 {