[perl #120511] QRegex: a zerowidth match of CCLASS_NEWLINE advances position by 1 if it matches \r\n

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# New Ticket Created by  Timo Paulssen 
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# <URL: https://rt.perl.org/Ticket/Display.html?id=120511 >


17:50 < timotimo> nqp: say("\r\na" ~~ /<?[\w]>"\r\na"/);
17:50 <+camelia> nqp-moarvm: OUTPUT«Substring length (-6) cannot be 
negative␤Str␤»
17:50 <+camelia> ..nqp-jvm, nqp-parrot: OUTPUT«␤»
17:50 < timotimo> nqp: say("\r\na" ~~ /"\r\na"/);
17:50 <+camelia> nqp-moarvm, nqp-jvm, nqp-parrot: OUTPUT«

the implementation of CCLASS_NEWLINE doesn't have a condition for the addition 
to pos if it matched a \r\n.

I'll fix this bug on a train ride today.