pytorch

b579433b - Revert D21487840: Bind VariableFunctions as a module, not a class with static methods.

Revert D21487840: Bind VariableFunctions as a module, not a class with static methods. Test Plan: revert-hammer Differential Revision: D21487840 Original commit changeset: 368da9b9c50e fbshipit-source-id: 900f5d36490ac8d419c6704f8727d4c8e492bfb7