Improve the speed of MapIter a bit.
Improve the speed of MapIter a bit.

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