pytorch

1314f7f4 - Ensure the original grad_mode is restored during backward (#31884)

Ensure the original grad_mode is restored during backward (#31884) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/31884 Fix #31715 Test Plan: Imported from OSS Differential Revision: D19301076 Pulled By: albanD fbshipit-source-id: 2d20c01bfb6364fa96c8fe5aa5ce7ea39defa3ce