Summary: Ref T4195. I need this for the Herald pre-commit rules, and it generally simplifies things.
Test Plan: Used `reparse.php` plus `var_dump()` to inspect refs in Git, Mercurial and SVN repos. They all looked correct and reparsed correctly.
Reviewers: btrahan
Reviewed By: btrahan
CC: aran
Maniphest Tasks: T4195
Differential Revision: https://secure.phabricator.com/D7804
