message: Small synthetic data fix
  Summary: Fix for infeeds when runnning hlo with synthetic data from C++, as there will be no infeed iterators setup.
  Test Plan: CI
  Reviewers: #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, georgep
  Maniphest Tasks: T9494
diff: @@ -863,6 +863,10 @@ void PoplarExecutor::ConnectInfeedsToStreamCallback(
  Status PoplarExecutor::SetupInfeedReplication(
  const TranslatedInfeedInfos& infeed_infos) {
  + if (UseSyntheticDataFor(SyntheticDataCategory::Infeed)) {
  + return Status::OK();
  + }
  +
  std::unique_lock<std::mutex> l(infeeds_mutex_);
  for (auto& infeed_info : infeed_infos) {
  const int64_t replication_factor = current_replication_factor_;
  