Fixed the generated wrappers for attributed function types.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>

src/AST/TypeExtensions.cs

@@ -179,6 +179,10 @@
                     return replacement.Desugar();
             }
 
+            var attributedType = t as AttributedType;
+            if (attributedType != null)
+                return attributedType.Equivalent.Type.Desugar();
+
             return t;
         }
 

tests/CSharpTemp/CSharpTemp.h

@@ -11,6 +11,7 @@ public:
     int& operator[](int i);
     int A;
     int* (*functionPtrReturnsPtrParam)();
+    int (__stdcall *attributedFunctionPtr)();
 
     static const int rename = 5;