[perl #88340] backreferences to quantified captures are inconsistent in rakudo

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# New Ticket Created by  Moritz Lenz 
# Please include the string:  [perl #88340]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=88340 >


10:49 < moritz> rakudo: say 'aaaa' ~~ /(\w)+$0/; say $0
10:49 <+p6eval> rakudo 4bf132: OUTPUT«aaaa␤a a a␤»
10:50 < moritz> huh. Is that correct?
10:50 < masak> don't think so.
10:51  * moritz facepalms
10:51 < moritz> $0 is an array
10:51 < moritz> what happens when you interpolate an array into a regex?
10:51 < moritz> you get an alternation, no?
10:52  * moritz presents the case to the Regex High Court of TimToady, 
pmichaud and sorear
10:52 < moritz> is that another "doctor, it hurts when I do this"? :-)
10:52 < masak> no.
10:52 < masak> this is bad.
10:53 < masak> you're clearly not intending $0 as an array, but as a 
submatch string.
10:54 < moritz> rakudo: say 'abcd' ~~ /(.)+$0/; say $0
10:54 <+p6eval> rakudo 4bf132: OUTPUT«␤␤»
10:54 < moritz> rakudo: say 'abca' ~~ /(.)+$0/; say $0
10:54 <+p6eval> rakudo 4bf132: OUTPUT«␤␤»
10:54 < moritz> rakudo: say 'abcc' ~~ /(.)+$0/; say $0
10:54 <+p6eval> rakudo 4bf132: OUTPUT«abcc␤a b c␤»
10:55 < moritz> ok that's not what it does
10:55 < moritz> it just takes the last item

I think it is inconsistent that $0 in the regex only matches $0[*-1], 
but is reported as the full array outside the regex.

I'm not sure what the desired behavior is.