If a declaration has a reference to a complete version of itself, then return the declaration as complete.

src/Generator/Types/Types.cs

@@ -11,6 +11,9 @@ namespace Cxxi
     {
         public override bool VisitDeclaration(Declaration decl)
         {
+            if (decl.CompleteDeclaration != null)
+                return true;
+
             return !decl.IsIncomplete;
         }