transitiveClosure as a stdlib function

Does anyone else think that a transitiveClosure function is a good idea to have in the kotlin-stdlib?

I raised a request here [https://youtrack.jetbrains.com/issue/KT-30675]
do comment (also) on the ticket, if you have any thoughts.

I’d also be interested in anyone who can provide a better (including faster) algorithm than the one in the ticket.

thanks