[perl #124121] Specialization causes mixing of arrays and lists to die

[via RT]

# New Ticket Created by  Brent Laabs 
# Please include the string:  [perl #124121]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=124121 >


Using the 'but' mixin, I seem to get a lot of NQP errors bubbling to the 
surface.

labster: m: 12 but ("hi", "ho");
camelia: rakudo-moar ac5f2e: OUTPUT«Cannot find method 'specialize'␤  in any 
compose at src/gen/m-Metamodel.nqp:2741␤  in any generate_mixin at 
src/gen/m-Metamodel.nqp:1267␤  in any  at src/gen/m-Metamodel.nqp:1188␤  in any 
mixin at src/gen/m-Metamodel.nqp:1223␤  in sub infix:<but>…»
labster: r: 12 but ("hi", "ho").list;
[camelia: rakudo-moar ac5f2e: OUTPUT«Cannot find method 'specialize'␤  in any 
compose at src/gen/m-Metamodel.nqp:2741␤  in any generate_mixin at 
src/gen/m-Metamodel.nqp:1267␤  in any  at src/gen/m-Metamodel.nqp:1188␤  in any 
mixin at src/gen/m-Metamodel.nqp:1223␤  in sub infix:<but>…»
labster: r: True but [ 1, 2 ]
camelia: rakudo-moar ac5f2e: OUTPUT«Cannot find method 'specialize'␤  in any 
compose at src/gen/m-Metamodel.nqp:2741␤  in any generate_mixin at 
src/gen/m-Metamodel.nqp:1267␤  in any  at src/gen/m-Metamodel.nqp:1188␤  in any 
mixin at src/gen/m-Metamodel.nqp:1223␤  in sub infix:<but>…»
labster: r: True but { "foo" => "bar" }
camelia: rakudo-moar 66a5bb: ( no output )