message: Back out "Assert that a mergeable must have a ctor"
  Summary: Original commit changeset:
diff: @@ -1081,8 +1081,9 @@ void Model::collect_methods() {
  }
  merger.dmethods.emplace_back(method);
  }
  - always_assert_log(has_ctor, "[TERA] No ctor found for mergeable %s",
  - SHOW(type));
  + if (!has_ctor) {
  + TRACE(TERA, 2, "[TERA] No ctor found for mergeable %s", SHOW(type));
  + }
  const auto& virt_scopes = m_type_system.get_class_scopes().get(type);
  TRACE(TERA, 8, "%ld virtual scopes in %s", virt_scopes.size(),
  