pytorch

578f0a04 - fix torch.nn.parallel.scatter_gather.gather to handle NamedTuples and handle moving output to CPU (#51104)

fix torch.nn.parallel.scatter_gather.gather to handle NamedTuples and handle moving output to CPU (#51104) Summary: Fixes #{[50510](https://github.com/pytorch/pytorch/issues/50510)} Allows ```torch.nn.parallel.scatter_gather.gather``` to accept a list of NamedTuples as input and returns a NamedTuple whose elements are tensors. I added the author's fix using the ```is_namedtuple``` function. While testing this fix, I encountered a deprecation warning instructing me to use ```'cpu'``` instead of ```-1``` to move the outputs to the CPU. However, doing this causes an assertion error in the ```_get_device_index``` function. I solved this by handling the CPU case in the affected ```forward``` function. rohan-varma Pull Request resolved: https://github.com/pytorch/pytorch/pull/51104 Reviewed By: albanD Differential Revision: D26395578 Pulled By: rohan-varma fbshipit-source-id: 6e98c9ce1d9f1725973c18d24a6554c1bceae465