message: Convert schema assert for duplicate type names to exception
diff: @@ -513,7 +513,10 @@ OpSchema& OpSchema::TypeConstraint(
  std::string type_str,
  std::vector<std::string> constraints,
  std::string description) {
  - assert(type_constraints_.end() == type_constraints_.find(type_str));
  + if (type_constraints_.end() != type_constraints_.find(type_str)) {
  + fail_schema("Duplicate type constraint name");
  + }
  +
  DataTypeSet d;
  for (const auto& t : constraints) {
  d.insert(Utils::DataTypeUtils::ToType(t));
  