Tensor method rename size()->numel() - 2/3 (#16745)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16745
Codemod generated with clangr shard mode, 25 files per diff,
Reviewed By: dzhulgakov
Differential Revision: D13944353
fbshipit-source-id: 25c2ca22204706544ee67e59c663bf495f2b4f6b
