Implement support for .= to init sigilless vars
Implement support for .= to init sigilless vars

Phixes https://github.com/rakudo/rakudo/issues/1461

tbrowder/rakudo,tony-o/rakudo,nbrown/rakudo,salortiz/rakudo,rakudo/rakudo,Gnouc/rakudo,lucasbuchala/rakudo,labster/rakudo,rakudo/rakudo,lucasbuchala/rakudo,tbrowder/rakudo,salortiz/rakudo,tbrowder/rakudo,lucasbuchala/rakudo,softmoth/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,softmoth/rakudo,tony-o/rakudo,MasterDuke17/rakudo,softmoth/rakudo,MasterDuke17/rakudo,labster/rakudo,Gnouc/rakudo,lucasbuchala/rakudo,tbrowder/rakudo,MasterDuke17/rakudo,labster/rakudo,salortiz/rakudo,softmoth/rakudo,Gnouc/rakudo,lucasbuchala/rakudo,nbrown/rakudo,MasterDuke17/rakudo,salortiz/rakudo,tony-o/rakudo,nbrown/rakudo,Gnouc/rakudo,Gnouc/rakudo,salortiz/rakudo,nbrown/rakudo,nbrown/rakudo,rakudo/rakudo,rakudo/rakudo,softmoth/rakudo,rakudo/rakudo,nbrown/rakudo,rakudo/rakudo,tony-o/rakudo,tony-o/rakudo,labster/rakudo,tony-o/rakudo,tbrowder/rakudo,salortiz/rakudo,labster/rakudo,labster/rakudo,Gnouc/rakudo,MasterDuke17/rakudo