[PyTorch] AOTI: Add aoti_torch_assign_tensors to ABI (#110909)
I need this to do a cheap and easy output copy in D50023678.
Differential Revision: [D50105080](https://our.internmc.facebook.com/intern/diff/D50105080/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110909
Approved by: https://github.com/jansel, https://github.com/chenyang78, https://github.com/desertfire
ghstack dependencies: #110876, #110877
