Uninitialized Ivalue (#21387)
Summary:
Create an uninitialized ivalue. This will be needed for Breaks & Continues to match up if block outputs of values that are guaranteed not to be used but need to escape the block scope. It is not exposed to users.
Was previously part of final returns but I was asked to make a separate PR for it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21387
Differential Revision: D15745124
Pulled By: eellison
fbshipit-source-id: ae6a6f766b4a70a71b9033987a630cfbf044e296
