Don't call cudaStreamDestroy at destruction time (#15692)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15692
It was leading to ocassional crashes with dynamically linked CUDA because runtime was already destroyed.
Also, unique_ptr<T[]> is more suitable than deque<T> for the purpose.
Reviewed By: Yangqing
Differential Revision: D13571988
fbshipit-source-id: 37eb26dfbe361c49160367b53f87bd037c6c0e46
