Make aten.copy preserve strides (hf_Longformer) (#89464)
Fixes https://github.com/pytorch/torchdynamo/issues/1888
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Differential Revision: [D41460986](https://our.internmc.facebook.com/intern/diff/D41460986)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89464
Approved by: https://github.com/bdhirsh
