Summary: D2728 added some extensions as builtin functions to the symbol map, but users may have old caches which still list these dependencies. Bump the symbol cache version; @nodren reported that dropping caches fixed the issue for him.
Test Plan: Ran "arc lint", got cache rebuilds.
Reviewers: vrana, nodren
Reviewed By: vrana
CC: aran
Maniphest Tasks: T1347
Differential Revision: https://secure.phabricator.com/D2746
