[get rid of unused functions in E/Rules
John Meacham <john@repetae.net>**20060410061651] hunk ./E/Rules.hs 14
-    hasBuiltinRule,
hunk ./E/Rules.hs 21
-    ruleFreeVars,
hunk ./E/Rules.hs 113
-ruleFreeVars ::  Rules -> TVr -> IdSet
-ruleFreeVars (Rules r) tvr = case Map.lookup (tvrIdent tvr) r of
-    Nothing -> mempty
-    Just rs -> (freeVars (map ruleBody rs) S.\\ freeVars (map ruleArgs rs))
hunk ./E/Rules.hs 241
-hasBuiltinRule TVr { tvrIdent = n } = n `Set.member` Set.fromList [preludeError]