Fixed missing symbols

Summary: Some symbols/files that are not defined have crept into the `__phutil_library_map__.php` file. In this revision, I fix this problem by running `arc liberate`, and also add a unit test to prevent this from occuring in the future (the unit test was taken from Phabricator).

Test Plan: `arc unit`

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D8056