[src/builtins/Mu.pir] added .list method
[src/builtins/Mu.pir] added .list method

This makes all the tests in t/spec/S12-enums/anonymous.t pass.

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