[reapply][JIT] Namespaces for TorchBind (#35254)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35254
Reapply D20541090 with some BC fixes
ghstack-source-id: 100733987
Test Plan: buck test mode/dev-nosan //caffe2/torch/fb/predictor/model_repo/tests:ai_infra_representative_model_shard_6_test -- 'RepresentativeModelTest\/ShardedRepresentativeModelTest\.RunModel\/0'
Reviewed By: zdevito
Differential Revision: D20607111
fbshipit-source-id: 80f148d860571208c93e9308128cd480ff089f74
