message: Z3: disable ematching and rely solely on MBQI
  gives a ~3x speedup
diff: @@ -12,6 +12,7 @@ context ctx;
  void context::init() {
  auto config = Z3_mk_config();
  Z3_set_param_value(config, "timeout", get_query_timeout());
  + Z3_global_param_set("smt.ematching", "false");
  ctx = Z3_mk_context_rc(config);
  Z3_del_config(config);
  }
  