* ostruct.rb: keep NoMethodError message with Ruby itself.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@3047 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

lib/ostruct.rb

@@ -30,7 +30,7 @@ class OpenStruct
     elsif args.length == 0
       @table[mid]
     else
-      raise NoMethodError, "undefined method `#{mname}'", caller(1)
+      raise NoMethodError, "undefined method `#{mname}' for #{self}", caller(1)
     end
   end