Investigate run time of validate-regions

[httphypixelnet]

As of 1a2066e, the validate-regions script is taking upwards of 15 seconds to run. I'd like to investigate if this is an issue in the code

[samfreund]

Part of the issue is likely that it doesn't run on solely staged files, it'll run on everything iirc.

[httphypixelnet]

slight improvement, PRing