Added helper declaration to represent delegates.

src/Bridge/Delegate.cs

@@ -0,0 +1,12 @@
+namespace Cxxi
+{
+    public class Delegate : Declaration
+    {
+        public FunctionType Type;
+
+        public override T Visit<T>(IDeclVisitor<T> visitor)
+        {
+            return visitor.VisitDeclaration(this);
+        }
+    }
+}