R1:62143b5455e7

Add modern Unit/Lint field support

Summary: Ref T2222. This is mostly copy/paste. No effect yet.

Test Plan: Looked at fields.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T2222

Differential Revision: https://secure.phabricator.com/D8360