repositories can end up in bad state and harm overall system

Created by: slimsag

The file tree on the left doesn't load for 10s+ and other Git operations in this repo similarly take a very long time.

Looks like this has been happening and causes our alert to flicker since at least as far back as June 7th: https://sourcegraph.slack.com/archives/C0J618TTM/p1559938399002800

Possibilities:

• Possible regression somewhere, or gitserver experiencing more load elsewhere in prod than usual?
• The repo needs to be GC'd? Do we have something that git gc's periodically? (I think so)
• The repo has grown so large we can't support it anymore (unlikely)