registration options should only be callable on rvalues (#21079)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21079
They're invalidating *this, so they shouldn't be callable on non-rvalues.
Reviewed By: dzhulgakov
Differential Revision: D15541583
fbshipit-source-id: a2a9dafb29af03477486ea2ce9029399f557c728
