Add constructor for ArgumentDef (#47492)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/47493
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47492
Reviewed By: bdhirsh
Differential Revision: D24791564
Pulled By: dzhulgakov
fbshipit-source-id: 43e4bbda754c61f40855675c1d5d0ddc9f351ebe
