pytorch

b7687772 - Added math.log2 and hypot

Added math.log2 and hypot Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/21512 Test Plan: Imported from OSS Differential Revision: D16088191 Pulled By: Chillee fbshipit-source-id: 5d80c480243d2644c96df26337cf65918d79443e