removing special code generator setup for hd and last function because this causes problems with quickcheck narrowing as the Haskell Prelude functions throw errors that cannot be caught instead of PatternFail exceptions
--- a/src/HOL/List.thy Thu Dec 08 13:46:04 2011 +0100
+++ b/src/HOL/List.thy Thu Dec 08 13:53:27 2011 +0100
@@ -5312,12 +5312,6 @@
code_const dropWhile
(Haskell "dropWhile")
-code_const hd
- (Haskell "head")
-
-code_const last
- (Haskell "last")
-
code_const list_all
(Haskell "all")