fix codgen for ."$var"()
fix codgen for ."$var"()

it used to call the get_string vtable, now uses an explicit unbox_s

zhuomingliang/rakudo,cognominal/rakudo,MasterDuke17/rakudo,skids/rakudo,azawawi/rakudo,usev6/rakudo,nunorc/rakudo,laben/rakudo,azawawi/rakudo,jonathanstowe/rakudo,ugexe/rakudo,zhuomingliang/rakudo,laben/rakudo,tony-o/deb-rakudodaily,niner/rakudo,rakudo/rakudo,softmoth/rakudo,lucasbuchala/rakudo,awwaiid/rakudo,tony-o/deb-rakudodaily,ungrim97/rakudo,nunorc/rakudo,Gnouc/rakudo,dwarring/rakudo,raydiak/rakudo,dwarring/rakudo,teodozjan/rakudo,jonathanstowe/rakudo,salortiz/rakudo,cognominal/rakudo,LLFourn/rakudo,retupmoca/rakudo,b2gills/rakudo,skids/rakudo,labster/rakudo,b2gills/rakudo,samcv/rakudo,raydiak/rakudo,ungrim97/rakudo,raydiak/rakudo,lucasbuchala/rakudo,tony-o/deb-rakudodaily,MasterDuke17/rakudo,paultcochrane/rakudo,tbrowder/rakudo,rjbs/rakudo,azawawi/rakudo,Leont/rakudo,sjn/rakudo,sergot/rakudo,ab5tract/rakudo,jonathanstowe/rakudo,softmoth/rakudo,tony-o/rakudo,ugexe/rakudo,skids/rakudo,labster/rakudo,samcv/rakudo,ugexe/rakudo,lucasbuchala/rakudo,ugexe/rakudo,ungrim97/rakudo,cognominal/rakudo,retupmoca/rakudo,softmoth/rakudo,zostay/rakudo,sergot/rakudo,tony-o/rakudo,tony-o/rakudo,laben/rakudo,tony-o/rakudo,jonathanstowe/rakudo,paultcochrane/rakudo,cygx/rakudo,b2gills/rakudo,nbrown/rakudo,b2gills/rakudo,pmurias/rakudo,rakudo/rakudo,dankogai/rakudo,MasterDuke17/rakudo,rjbs/rakudo,paultcochrane/rakudo,usev6/rakudo,salortiz/rakudo,teodozjan/rakudo,paultcochrane/rakudo,labster/rakudo,Gnouc/rakudo,rakudo/rakudo,rakudo/rakudo,dwarring/rakudo,paultcochrane/rakudo,tony-o/rakudo,niner/rakudo,nunorc/rakudo,salortiz/rakudo,samcv/rakudo,salortiz/rakudo,Leont/rakudo,tbrowder/rakudo,tbrowder/rakudo,ab5tract/rakudo,awwaiid/rakudo,sjn/rakudo,niner/rakudo,cygx/rakudo,teodozjan/rakudo,jonathanstowe/rakudo,dwarring/rakudo,cognominal/rakudo,cygx/rakudo,raydiak/rakudo,sergot/rakudo,samcv/rakudo,LLFourn/rakudo,retupmoca/rakudo,pmurias/rakudo,pmurias/rakudo,nbrown/rakudo,softmoth/rakudo,lucasbuchala/rakudo,tony-o/deb-rakudodaily,rjbs/rakudo,zhuomingliang/rakudo,zostay/rakudo,zhuomingliang/rakudo,cygx/rakudo,azawawi/rakudo,labster/rakudo,rakudo/rakudo,ungrim97/rakudo,zostay/rakudo,azawawi/rakudo,dankogai/rakudo,LLFourn/rakudo,retupmoca/rakudo,salortiz/rakudo,ab5tract/rakudo,nbrown/rakudo,sergot/rakudo,MasterDuke17/rakudo,tbrowder/rakudo,teodozjan/rakudo,Gnouc/rakudo,cygx/rakudo,niner/rakudo,Gnouc/rakudo,nbrown/rakudo,tbrowder/rakudo,tony-o/rakudo,salortiz/rakudo,dankogai/rakudo,tbrowder/rakudo,usev6/rakudo,ab5tract/rakudo,ugexe/rakudo,MasterDuke17/rakudo,usev6/rakudo,Leont/rakudo,lucasbuchala/rakudo,awwaiid/rakudo,pmurias/rakudo,softmoth/rakudo,Leont/rakudo,ungrim97/rakudo,MasterDuke17/rakudo,b2gills/rakudo,dankogai/rakudo,skids/rakudo,tony-o/deb-rakudodaily,usev6/rakudo,Gnouc/rakudo,labster/rakudo,labster/rakudo,dankogai/rakudo,laben/rakudo,ab5tract/rakudo,nbrown/rakudo,nbrown/rakudo,samcv/rakudo,zostay/rakudo,awwaiid/rakudo,sjn/rakudo,LLFourn/rakudo,sjn/rakudo,rakudo/rakudo,nunorc/rakudo,tony-o/deb-rakudodaily,sjn/rakudo,LLFourn/rakudo,awwaiid/rakudo,skids/rakudo,cognominal/rakudo,tony-o/deb-rakudodaily,Gnouc/rakudo