message: Add tensor read dependencies for swap-out stmts
diff: @@ -1827,6 +1827,7 @@ stripe::StatementIt Scheduler::ScheduleSwapOut(stripe::StatementIt si, CacheEntr
  }
  }
  ent->source->saw_final_write = true;
  + ent->readers.emplace(swap_out_it->get(), ent->source->alias_info);
  return swap_out_it;
  }
  