escape backward slash in stack trace in Windows to slash (#60842)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/60187
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60842
Reviewed By: gdankel
Differential Revision: D29498498
Pulled By: malfet
fbshipit-source-id: 78e1b25a2e6bdfd3ba0c988d023c7a7f79a22cf4
