message: reserve on m_toplevel in WPO
diff: @@ -528,6 +528,7 @@ class WpoBuilder final {
  }
  // Add scheduling constraints between the WPOs for maximal SCCs.
  + m_toplevel.reserve(get_next_dfn());
  for (uint32_t v = 1; v < get_next_dfn(); v++) {
  if (rep[dsets.find_set(v)] == v) {
  add_toplevel(v);
  