message: Fix compilation issue because atomic is not copyable.
diff: @@ -64,7 +64,10 @@ void RunSharding(int64 block_size, int64 total, ThreadPool* threads) {
  mutex mu;
  int64 num_shards = 0;
  int64 num_done_work = 0;
  - std::vector<std::atomic<bool>> work(total, false);
  + std::vector<std::atomic<bool>> work(total);
  + for (int i = 0; i < total; i++) {
  + work[i] = false;
  + }
  threads->TransformRangeConcurrently(
  block_size, total,
  [=, &mu, &num_shards, &num_done_work, &work](int64 start, int64 end) {
  