Fixed incompilable code generated by the C++/CLI back-end when wrapping certain unions.

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

src/Generator/Generators/CLI/CLISourcesTemplate.cs

@@ -662,7 +662,8 @@ namespace CppSharp.Generators.CLI
                 {
                     ArgName = property.Name,
                     ReturnVarName = nativeField,
-                    ReturnType = property.QualifiedType
+                    ReturnType = property.QualifiedType,
+                    Declaration = property.Field
                 };
 
                 var marshal = new CLIMarshalNativeToManagedPrinter(ctx);

tests/Basic/Basic.h

@@ -602,14 +602,24 @@ public:
 
 DLL_API void va_listFunction(va_list v);
 
-struct DLL_API TestEmptyName
+struct DLL_API TestNestedTypes
 {
+public:
     struct
     {
         struct
         {
         };
     };
+
+    union as_types
+    {
+        int as_int;
+        struct uchars
+        {
+            unsigned char blue, green, red, alpha;
+        } as_uchar;
+    };
 };
 
 class DLL_API HasStdString