Summary: Useful if you run CLion.
Test Plan: built everything.
Reviewers: #fastmanifest, durham
Reviewed By: durham
Subscribers: mitrandir
Differential Revision: https://phabricator.intern.facebook.com/D3700542
Signature: t1:3700542:1471382263:260eb0a1588480f1d4c798df60d559c63ed19c8a