static graph api skeleton (#54995)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54995
provide an DDP private API to explicitly set the training is static, also set this flag in logger
ghstack-source-id: 127755713
Test Plan: unit tests
Reviewed By: rohan-varma
Differential Revision: D27444965
fbshipit-source-id: 06ef1c372296815944b2adb33fbdf4e1217c1359
