pytorch

44997efd - [PyTorch] Move get_nested_tensor_impl to header (#73998)

[PyTorch] Move get_nested_tensor_impl to header (#73998) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/73998 For reuse elsewhere. ghstack-source-id: 150983356 Test Plan: CI Reviewed By: ezyang Differential Revision: D34647899 fbshipit-source-id: 0a11859bfaaa84f095e1fd10244a6a58c4071608 (cherry picked from commit de5026915fdc80cd704e7783b63e859e2cf045df)