pytorch

e0b958f9 - [SPMD] Allow IterGraph support a more general subgraph movement (#98360)

[SPMD] Allow IterGraph support a more general subgraph movement (#98360) Resubmit D44444398 due to the merging conflict. The original assumption of IterGraph is very restrictive and only allow users to move a subgraph that only one node has the input from external nodes. This PR fixes the limitation. Differential Revision: [D44689730](https://our.internmc.facebook.com/intern/diff/D44689730/) **NOTE FOR REVIEWERS**: This PR has internal Meta-specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D44689730/)! Pull Request resolved: https://github.com/pytorch/pytorch/pull/98360 Approved by: https://github.com/lessw2020