Change the codegen so GC info can be emitted.
Change the codegen so GC info can be emitted.

varjagg/Mezzano,AugustusHuang/Mezzano,rvedam/Mezzano,froggey/Mezzano,varjagg/Mezzano,rvedam/Mezzano,froggey/Mezzano,AugustusHuang/Mezzano