Eliminated index reference to super
Eliminated index reference to super

I don't think it actually exists. It's not in rakudo or in the design
documents. Closes #2076.

tbrowder/doc,jonathanstowe/doc,tbrowder/doc,MasterDuke17/doc,jonathanstowe/doc,MasterDuke17/doc,stmuk/doc,perl6/doc,perl6/doc,jonathanstowe/doc,dmaestro/doc,stmuk/doc,MasterDuke17/doc,dmaestro/doc,dmaestro/doc,tbrowder/doc,perl6/doc,perl6/doc,stmuk/doc,MasterDuke17/doc,stmuk/doc,stmuk/doc,jonathanstowe/doc,dmaestro/doc,jonathanstowe/doc,perl6/doc,dmaestro/doc,tbrowder/doc