Go was inspired by several systems that have come before it. You can write coroutine code with channels in C.

http://man.cat-v.org/plan_9/2/thread

It’s available for unix systems as well in the Plan9Port, and that predates Go by a bit.

I’m not sure what any of this has to do with Clojure though other than to say “look we have Go-like concurrency without starting over”. It’s been shown that you don’t have to start over to add features to other languages as well.

See also libmill http://libmill.org/

Go was not solely created to have goroutines and channels, but that was definitely one of the features desired.