All tests should result in exceptions being thrown.
exception(univ_cons(software_error("predicate `string.from_char_list\'/2: Unexpected: null character or surrogate code point in list")))
exception(univ_cons(software_error("predicate `string.from_rev_char_list\'/2: Unexpected: null character or surrogate code point in list")))
exception(univ_cons(software_error("predicate `string.set_char\'/4: Unexpected: null character")))
exception(univ_cons(software_error("predicate `string.unsafe_set_char\'/4: Unexpected: null character")))
error("", io_error_string("null character in input"))
error(io_error_string("null character in input"))