message: Do not clobber resource update sequence
  Summary:
  Do not override the sequence - some copies might have been added.
  Fixes T27462
  Test Plan: All tests pass
  Reviewers: hakons, jakeh, #tensorflow, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved
  Maniphest Tasks: T27462
diff: @@ -1447,10 +1447,10 @@ Status PipelineVisitor::HandleDeferredAllocationCall(HloInstruction* hlo) {
  TF_ASSIGN_OR_RETURN(DeferredArgRBVectors inputs,
  GetInputsForDeferredInplaceRBInstruction(
  hlo, /*preserve_aliasing*/ true));
  -
  - TF_ASSIGN_OR_RETURN(resource_update_,
  + TF_ASSIGN_OR_RETURN(poplar::program::Sequence seq,
  CreateResourceUpdateOp(resources_, hlo, inputs,
  hlo->shape(), tensor_map));
  + resource_update_.add(seq);
  } else {
  TF_ASSIGN_OR_RETURN(auto stage, GetPipelineStage(inst_stage_mapping_, hlo));
  