Avoid super in define_method for Rubinius

actionpack/lib/action_dispatch/http/mime_type.rb

@@ -10,7 +10,12 @@ module Mime
     %w(<< concat shift unshift push pop []= clear compact! collect!
     delete delete_at delete_if flatten! map! insert reject! reverse!
     replace slice! sort! uniq!).each do |method|
-      define_method(method) {|*args| @symbols = nil; super(*args) }
+      module_eval <<-CODE
+        def #{method}(*args)
+          @symbols = nil
+          super
+        end
+      CODE
     end
   end