Summary:
Ref T5501. This is just getting version detection and availability right, probably.
Eventually, this will get lifted up a bit and "$remedy" will turn into setup issues (or maybe one setup issue saying "your cache setup is messed up, click here to understand why").
Test Plan:
{F362935}
I intend to shove these up to production one-by-one since production is APC and local is Opcache + APCu.
Reviewers: btrahan
Reviewed By: btrahan
Subscribers: epriestley
Maniphest Tasks: T5501
Differential Revision: https://secure.phabricator.com/D12314
