[perl #123956] [BUG] multi-name argument parsing too strict

[via RT]

# New Ticket Created by  Alexander Moquin 
# Please include the string:  [perl #123956]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=123956 >


03:26 < Mouq> m: sub (:t(:$th)) {}
03:26 <+camelia> rakudo-moar 61c59d: ( no output )
03:26 < Mouq> m: sub (:t( :$th )) {}
03:26 <+camelia> rakudo-moar 61c59d: OUTPUT«===SORRY!=== Error while
compiling /tmp/0yAAc9tKQn␤Unable to parse named parameter; couldnt find
right parenthesis␤at /tmp/0yAAc9tKQn:1␤------> sub (:t( :$th⏏ )) {}␤
expecting any of:␤        shape declaration␤»
03:26 < Mouq> std: sub (:t( :$th )) {}
03:26 <+camelia> std 28329a7: OUTPUT«ok 00:00 138m␤»
03:26  * Mouq rakudobugs

The bug is that sub (:t( :$th )) {} should parse the same as sub (:t(:$th))
{}