default_collate should collate bool list to byte tensors (#14669)
Summary:
Based on #15331 . Review only the last commit.
Fixes https://github.com/pytorch/pytorch/issues/14507.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14669
Reviewed By: ezyang
Differential Revision: D13528725
Pulled By: soumith
fbshipit-source-id: f12f1ac1c4ff2a3ddd6877c0c096a5da3a1ffa3c
