[perl #74844] Classes inheriting from Array don't have working postcircumfix methods

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# New Ticket Created by  Moritz Lenz 
# Please include the string:  [perl #74844]
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# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=74844 >


13:53 <@moritz_> rakudo: class A is Array { }; my $a = A.new; $a[0] = 'baz'
13:53 <+p6eval> rakudo c4857a: OUTPUT«Null PMC access in
invoke()␤current instr.: 'perl6;Proxy;!STORE' pc 14609
                (src/builtins/Routine.pir:151)␤»