Now that coroutine-jre8 is included, why not include the standard lib for jre8?

I can imagine that doing so will lead to more complex issues (e.g. separate builds), but this can also provide those java 8 features to kotlin. So please consider about this.

Or wait for Minecraft 1.12 Release?

Whoops, forgot to add that one. I'll release an new version with it soon.

When?