Fix `cons` implementation post GLR
Fix `cons` implementation post GLR

perl6/perl6-examples,shlomif/perl6-examples,perl6/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,shlomif/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples