implement a function to convert a storage to copy-on-write (#100819)
implement a function to convert a storage to copy-on-write
Summary:
This will be used in the _lazy_clone() operator as well as reshape().
Test Plan: 100% coverage of reachable lines.
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* #100821
* #100820
* __->__ #100819
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100819
Approved by: https://github.com/ezyang
