Turn resolver into a class (#19236)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19236
ghimport-source-id: d36705ea5ecff085d0d84ea57bb96d18d7c260dd
Differential Revision: D14928292
Reviewed By: zdevito
Pulled By: suo
fbshipit-source-id: cd038100ac423fa1c19d0547b9e5487a633a2258
