fixup! Implement __builtin_ctz{,l,ll} via count_trailing_zeros_exprt

Author: tautschnig

src/util/simplify_expr.cpp

@@ -178,7 +178,9 @@ simplify_exprt::resultt<>
 simplify_exprt::simplify_ctz(const count_trailing_zeros_exprt &expr)
 {
   const auto const_bits_opt = expr2bits(
-    expr.op(), byte_extract_id() == ID_byte_extract_little_endian, ns);
+    expr.op(),
+    config.ansi_c.endianness == configt::ansi_ct::endiannesst::IS_LITTLE_ENDIAN,
+    ns);
 
   if(!const_bits_opt.has_value())
     return unchanged(expr);