Enabling lite interpreter in torch python API (#39181)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39181
Create a python binding classes torch._C. LiteScriptModule for mobile::module, a python class called LiteScriptModule is created which wrap torch._C. LiteScriptModule.
Python class LiteScriptModule contains preliminary functions including forward, run_method and __call__.
Create a python api "load_for_lite_interpreter" under torch.jit.mobile where takes pre-saved mobile module in a file-like object as input and returns python class LiteScriptModule.
Add a python binding method "_save_to_buffer_for_mobile" under ScriptModule, and python method "_save_to_buffer_for_lite_interpreter" under RecursiveScriptModule which saves mobile module into buffer instead of file.
ghstack-source-id: 105215736
Test Plan: buck test caffe2/test:mobile
Differential Revision: D21757474
fbshipit-source-id: 758b87497d65c4686459a567d41887c7a577aa4c
