Adds CUDA C++11 and Profiling Notes (#21386)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21386
ghimport-source-id: 9430c7640b90d9add38d9bf2f1bd0c8f62b7f239
Differential Revision: D15640102
Pulled By: ezyang
fbshipit-source-id: 98a5efdea9b1de05207ebd3624cb20acda9fe96b
