message: Another attempt to placate the Windows build
diff: @@ -1007,7 +1007,9 @@ void ForwardAccumulator<Gradient, BackwardFunction, TapeTensor>::Watch(
  if (existing == accumulated_gradients_.end()) {
  accumulated_gradients_.emplace(tensor_id, tangent);
  } else {
  - std::array<Gradient*, 2> to_aggregate({tangent, existing->second});
  + std::array<Gradient*, 2> to_aggregate;
  + to_aggregate[0] = tangent;
  + to_aggregate[1] = existing->second;
  // AggregateGradients steals a reference to each of its arguments. We
  // MarkAsResult on `tangent` above so we don't steal a reference to it.
  existing->second = vspace_.AggregateGradients(to_aggregate);
  