Fix some lint rendering issues when lines prior to other identical lines are removed
Summary: See PHI191. This is a rehash of an earlier fix, but we didn't have a test case for this half yet.
- Added a failing test, made it pass.
- Added a linter like the one in PHI191, ran it, got a valid lint result instead of an exception.
Reviewed By: amckinley
Differential Revision: https://secure.phabricator.com/D18759