It came from Qwaq/Terf so it ended up in http://ss3.gemstone.com/ss/AndreasSystemProfiler.  Further, as Levente says it depends on support that is in Cog VMs (JIT, Stack & Interpreter) but not (yet) in the trunk Interpreter.  So I guess it doesn't belong in trunk until the Cog Interpreter has been merged with the trunk Interpreter.  That's a fair amount of work, and neither David nor I have the time for it right now.