Make List.shift cheaper in the (common) case that we have an element. This in turn makes list assignment cheaper, wich does a gimme to ensure there is an element, followed by a shift.
Make List.shift cheaper in the (common) case that we have an element. This in turn makes list assignment cheaper, wich does a gimme to ensure there is an element, followed by a shift.

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