explizit serialization for Haskell id

--- a/src/HOL/Fun.thy	Wed Dec 27 19:09:54 2006 +0100
+++ b/src/HOL/Fun.thy	Wed Dec 27 19:09:55 2006 +0100
@@ -480,6 +480,9 @@
   (SML infixl 5 "o")
   (Haskell infixr 9 ".")
 
+code_const "id"
+  (Haskell "id")
+
 
 subsection {* ML legacy bindings *}