[SR] assignStorageToManagedTensors returns a vector (#69568)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69568
Non-empty vectors should never be passed to `assignStorageToManagedTensors` and `assignStorageToManagedOutputTensors`. Presumably, this out-variant convention was adopted to avoid move-assigning the corresponding attribtues in `MemoryPlanner`. But the cost of a vector move-assign is not high, and this function type signature is safer.
Test Plan: `buck test caffe2/bechmarks/static_runtime:static_runtime_cpptest`
Reviewed By: donaldong
Differential Revision: D32729289
fbshipit-source-id: 88f19de8eb89d8a4f1dd8bbd4d9e7f686e41888b
