message: Fix tupled sharding.
  Summary:
  Followup to T29597
  Resolves T35611
  Test Plan: CI tests
  Reviewers: #tensorflow, simonl, #framework_ip_review_-_any_oss_or_third-party_code_use_has_been_approved, georgep
  Maniphest Tasks: T35611
diff: @@ -330,8 +330,14 @@ StatusOr<HloInstruction*> ConvertAllUsersToGTEs(HloInstruction* const inst) {
  MakeGetTupleElementHlo(inst, tuple_index));
  if (inst->has_sharding()) {
  // If there is any sharding, then forward it.
  - gtes[tuple_index]->set_sharding(inst->sharding().GetSubSharding(
  - inst->shape(), ShapeIndex{tuple_index}));
  + auto sharding = inst->sharding();
  +
  + if (sharding.IsTuple()) {
  + gtes[tuple_index]->set_sharding(
  + sharding.GetSubSharding(inst->shape(), ShapeIndex{tuple_index}));
  + } else {
  + gtes[tuple_index]->set_sharding(sharding);
  + }
  }
  }
  // Create tuple.
  