[vala] Fix critical when calling generated enum to_string method

[Jürg Billeter <juergbi src gnome org>]

commit 2757bea9c750a828f40d3db3a18f4bfc933c28f3
Author: Jürg Billeter <j bitron ch>
Date:   Fri Jun 3 11:59:47 2011 +0200

    Fix critical when calling generated enum to_string method

 vala/valaenumvaluetype.vala |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/vala/valaenumvaluetype.vala b/vala/valaenumvaluetype.vala
index 8a5b7d6..c409763 100644
--- a/vala/valaenumvaluetype.vala
+++ b/vala/valaenumvaluetype.vala
@@ -1,6 +1,6 @@
 /* valaenumvaluetype.vala
  *
- * Copyright (C) 2009  Jürg Billeter
+ * Copyright (C) 2009-2011  Jürg Billeter
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -49,6 +49,8 @@ public class Vala.EnumValueType : ValueType {
 			to_string_method.access = SymbolAccessibility.PUBLIC;
 			to_string_method.external = true;
 			to_string_method.owner = type_symbol.scope;
+			to_string_method.this_parameter = new Parameter ("this", this);
+			to_string_method.scope.add (to_string_method.this_parameter.name, to_string_method.this_parameter);
 		}
 		return to_string_method;
 	}