I think this is an unnecessary addition.I use D for game dev, and I avoid the GC + malloc like the plague, however I don't want to have to litter my code with distractions like nogc, @noheap or whatever keyword we choose.
It's easy enough to avoid these without expanding the type system. I add trace statements to the GC in druntime, and just avoid calling malloc. I think this is a more practical solution to this problem than extending the language and cluttering my code.
