[perl #116220] [BUG] Can't talk about roles with unimplemented methods in Rakudo

[Christian Bartolomaeus via RT]

The above error happens no longer with all methods. Maybe now really just 
stringification methods are affected?

$ perl6 -e 'role Foo { method bar {...} }; say Foo.^name'
Foo

$ perl6 -e 'role Foo { method bar {...} }; say Foo.^methods'
bar

$ perl6-m -e 'role Foo { method bar {...} }; say Foo.perl'
Method 'bar' must be implemented by Foo because it is required by a role
  in any compose_method_table at src/gen/m-Metamodel.nqp:2493
  in any apply at src/gen/m-Metamodel.nqp:2503
  in any compose at src/gen/m-Metamodel.nqp:2650
  in any make_pun at src/gen/m-Metamodel.nqp:1531
  in any find_method at src/gen/m-Metamodel.nqp:1554
  in block <unit> at -e:1

$ perl6-m -e 'role Foo { method bar {...} }; say Foo.WHAT'
Method 'bar' must be implemented by Foo because it is required by a role
  in any compose_method_table at src/gen/m-Metamodel.nqp:2493
  in any apply at src/gen/m-Metamodel.nqp:2503
  in any compose at src/gen/m-Metamodel.nqp:2650
  in any make_pun at src/gen/m-Metamodel.nqp:1531
  in any find_method at src/gen/m-Metamodel.nqp:1554
  in sub say at src/gen/m-CORE.setting:17365
  in block <unit> at -e:1