[perl #77522] Rakudo allows unspace in /\ X/ but STD doesn't

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# New Ticket Created by  Paweł Pabian 
# Please include the string:  [perl #77522]
# in the subject line of all future correspondence about this issue. 
# <URL: http://rt.perl.org/rt3/Ticket/Display.html?id=77522 >


[18:51] <bbkr> rakudo: /\ X/ # unspace bug :) known?
[18:51] <p6eval> rakudo 6ccdcd:  ( no output )


[18:51] <bbkr> std: /\ X/
[18:51] <p6eval> std 32116: OUTPUT«Invalid conversion in sprintf: "%M" at 
STD.pm line 57284.␤===SORRY!===␤No unspace allowed in 
regex; if you meant to match the literal character, please enclose in single 
quotes (' ') or use a backslashed form like \x%M->{02}x at /tmp/p05dWQrWFG 
line 1:␤------>
[18:51] <p6eval> ..[3…