Improve handling of ArrayFlags

[mikeshardmind]

Summary

This is a micro-optimization. Figured since it was easy to improve on, and these need to be created for potentially a lot of events, it didn't hurt to do slightly better.

Why Discord did it this way instead of as an integer bitfield like everything reasonable is unknowable, but this does less work to get to the same result.

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)

[Rapptz]

I'd merge this but it's obscenely unreadable compared to the original code. It could use a small comment to clarify it for future readers.

[mikeshardmind]

I've added an in-depth comment on this. I don't know why Discord went this route with it, but better to make sure anyone reading it later has an explanation, some of what's done there would be obscure to future readers.

[Rapptz]

Thanks.