Summary:
This PR adds strings to the ast and implements them for print statements. Strings are lifted as attributes to the print node. They must be arguments to print itself, not as an argument for an object that is passed to print. If they are encountered elsewhere a NYI exception will be thrown.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/9324
Reviewed By: jramseyer
Differential Revision: D8807128
Pulled By: eellison
fbshipit-source-id: 984401ff458ed18d473c6d1bd86750e56c77d078