Interest in cleaning up primitive barriers?

[Roman Kennke]

Hello GC list,

I'm currently in the process of cleaning up some leftovers from earlier 
Shenandoah incarnation. I stumbled across primitive heap access, which 
is now unused (not implemented/overridden by any GC, afaict), and I'm 
wondering if we want to get rid of it. It involves a whole lot of access 
machinery and removing could reduce complexity considerably. WDYT?

Roman