R1:a234a712cd52

Disable autoload in search for internal class

Test Plan:
/diffusion/symbol/Exception/?jump=1&type=class&lang=php
/diffusion/symbol/Countable/?jump=1&type=class&lang=php

Reviewers: epriestley

Reviewed By: epriestley

CC: aran

Differential Revision: https://secure.phabricator.com/D2124