pytorch

74d91465 - build_variables.py: turn on link_whole for _C_impl library. (#18763)

build_variables.py: turn on link_whole for _C_impl library. (#18763) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/18763 Without `link_whole` flag in opt-builds some of the files are not linked into `_C_impl` library, which causes some of static initializers not to run (namely, registering an cutomPythonOperation from python_interpreter.cpp). This diff fixes it. Differential Revision: D14732471 fbshipit-source-id: 57cff6b4b6d479ad7ab7fd29f677746d91d6ff45