Update lang/ghc 8.4.2 and the hs-* ports the newer versions
* Update lang/ghc to 8.4.2
* Update the boostrap compiler to 8.4.1
* Update the many hs-* ports
* Bump the rest
Thanks a lot to arrowd for doing all the heavy lifting :)
PR: 227968
Exp-run by: antoine
Submitted by: arrowd
Differential Revision: https://reviews.freebsd.org/D15005