Adds back C::U, at least those that have been included; closes #1631
Adds back C::U, at least those that have been included; closes #1631

perl6/doc,tbrowder/doc,perl6/doc,perl6/doc,MasterDuke17/doc,perl6/doc,MasterDuke17/doc,MasterDuke17/doc,tbrowder/doc,tbrowder/doc,MasterDuke17/doc,perl6/doc,tbrowder/doc