Restore union bench
Restore union bench

This reverts commit a7dd3f0161056379e6f6c760f95614fae77dd4f7.

fpco/stackage,wereHamster/stackage,Shimuuar/stackage,codedmart/stackage,creichert/stackage,peti/stackage,mrkkrp/stackage,int-index/stackage,stackbuilders/stackage,jonschoning/stackage,spencerjanssen/stackage,michalkonecny/stackage,clinty/stackage,jaspervdj/stackage,asr/stackage,fimad/stackage,GregorySchwartz/stackage,garetxe/stackage,athanclark/stackage,Daniel-Diaz/stackage,lwm/stackage,ygale/stackage,brendanhay/stackage,phadej/stackage,simonmichael/stackage,soenkehahn/stackage,l29ah/stackage,massysett/stackage,DanielG/stackage,christiaanb/stackage,mstksg/stackage,iand675/stackage,alanz/stackage,mgajda/stackage,phaazon/stackage,judah/stackage,k0ral/stackage,ethercrow/stackage