Completed addition and testing of new add_serializable option.
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
index 3d818a6..8e8aff0 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
@@ -76,9 +76,9 @@
           "dGVuc2lvbl9udW1iZXISJy5wcm90b2J1Zl91bml0dGVzdF9leHRyYS5UZXN0" + 

           "WG1sTWVzc2FnZRhnIAMoBUICEAE6bgoRZXh0ZW5zaW9uX21lc3NhZ2USJy5w" + 

           "cm90b2J1Zl91bml0dGVzdF9leHRyYS5UZXN0WG1sTWVzc2FnZRjHASABKAsy" + 

-          "KS5wcm90b2J1Zl91bml0dGVzdF9leHRyYS5UZXN0WG1sRXh0ZW5zaW9uQkxI" + 

-          "AcI+RwohR29vZ2xlLlByb3RvY29sQnVmZmVycy5UZXN0UHJvdG9zEiJVbml0" + 

-          "VGVzdFhtbFNlcmlhbGl6ZXJUZXN0UHJvdG9GaWxl");

+          "KS5wcm90b2J1Zl91bml0dGVzdF9leHRyYS5UZXN0WG1sRXh0ZW5zaW9uQk5I" + 

+          "AcI+SQohR29vZ2xlLlByb3RvY29sQnVmZmVycy5UZXN0UHJvdG9zEiJVbml0" + 

+          "VGVzdFhtbFNlcmlhbGl6ZXJUZXN0UHJvdG9GaWxlSAE=");

       pbd::FileDescriptor.InternalDescriptorAssigner assigner = delegate(pbd::FileDescriptor root) {

         descriptor = root;

         internal__static_protobuf_unittest_extra_TestXmlChild__Descriptor = Descriptor.MessageTypes[0];

@@ -134,6 +134,7 @@
   #endregion

   

   #region Messages

+  [global::System.SerializableAttribute()]

   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -264,6 +265,7 @@
       return (Builder) new Builder().MergeFrom(prototype);

     }

     

+    [global::System.SerializableAttribute()]

     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -443,6 +445,7 @@
     }

   }

   

+  [global::System.SerializableAttribute()]

   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -532,6 +535,7 @@
       return (Builder) new Builder().MergeFrom(prototype);

     }

     

+    [global::System.SerializableAttribute()]

     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -641,6 +645,7 @@
     }

   }

   

+  [global::System.SerializableAttribute()]

   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -746,6 +751,7 @@
       return (Builder) new Builder().MergeFrom(prototype);

     }

     

+    [global::System.SerializableAttribute()]

     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -903,6 +909,7 @@
     }

   }

   

+  [global::System.SerializableAttribute()]

   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -935,6 +942,7 @@
     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

     public static class Types {

+      [global::System.SerializableAttribute()]

       [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

       [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

       [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -1065,6 +1073,7 @@
           return (Builder) new Builder().MergeFrom(prototype);

         }

         

+        [global::System.SerializableAttribute()]

         [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

         [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

         [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -1441,6 +1450,7 @@
       return (Builder) new Builder().MergeFrom(prototype);

     }

     

+    [global::System.SerializableAttribute()]

     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -1792,6 +1802,7 @@
     }

   }

   

+  [global::System.SerializableAttribute()]

   [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

   [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

   [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]

@@ -1898,6 +1909,7 @@
       return (Builder) new Builder().MergeFrom(prototype);

     }

     

+    [global::System.SerializableAttribute()]

     [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

     [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

     [global::System.CodeDom.Compiler.GeneratedCodeAttribute("ProtoGen", "2.3.0.277")]