Seems to be a regression from bug 715737. I'm quite certain this was broken before though, it was just hidden by the order in which we inserted movegroups.
Created attachment 587759 [details] [diff] [review]
The fix itself is small, but this also removes the outputMoves movegroup, since we don't really need it if we give blocks an exit movegroup. Every VirtualRegister now has only 2 movegroups, before and after.