message: Fix pipeline recomp message
  Summary: Fix T36848
  Test Plan: CI
  Reviewers: markf, #tensorflow, simonl, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved
  Subscribers: godfrey.da.costa
  Maniphest Tasks: T36848
diff: @@ -436,7 +436,15 @@ StatusOr<bool> PipelineRecomputation::RecomputePipeline(
  GetRecomputationCluster(fwd_stage, oi_info, last_stage));
  if (cluster_info.instructions.empty()) {
  - LOG(INFO) << "Cannot recompute pipline stage " << fwd_stage->ToString();
  + if (cluster_info.recomputation_checkpoints.size()) {
  + LOG(INFO) << "Found checkpoint instructions in pipeline stage "
  + << stage_id
  + << ", however could not find any operations which can be "
  + "recomputed.";
  + } else if (!last_stage) {
  + LOG(INFO) << "Cannot recompute pipeline stage " << stage_id << " ("
  + << fwd_stage->ToString() << ")";
  + }
  continue;
  }
  