[perl #127359] Weirdness with passing named to multi infixes

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# New Ticket Created by  Zoffix Znet 
# Please include the string:  [perl #127359]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=127359 >


In the first example blow, passing a named "foo" argument after a comma 
generates the "Unexpected named param passed..." warning and the $foo variable 
inside my multi is empty. Note that "meow" *was* printed, showing my custom sub 
was indeed called.

In the second example, we did not use a comma before the named "foo" argument; 
we're still getting the "Unexpected param" warning, but now our multi is not 
called.

Expected behaviour for both cases is our defined multi is called and the :foo 
argument is passed in as the named $foo parameter.


<ZoffixWin> m: multi sub infix:<+> (Int:D $a, Int:D $b, :$foo) {say "meow 
<$foo>"}; say say 42 + 1, :foo<42>;
<camelia> rakudo-moar d67cb0: OUTPUT«Use of uninitialized value $foo of type 
Any in string context␤Any of .^name, .perl, .gist, or .say can stringify 
undefined things, if needed.  in sub infix:<+> at /tmp/OT3Cjm5qF9 line 1␤meow 
<>␤Unexpected named parameter 'foo' passed␤  in block <un…»
<ZoffixWin> m: multi sub infix:<+> (Int:D $a, Int:D $b, :$foo) {say "meow 
<$foo>"}; say 42 + 1 :foo<42>;
<camelia> rakudo-moar d67cb0: OUTPUT«Unexpected named parameter 'foo' passed␤  
in block <unit> at /tmp/0eAa6uTt5N line 1␤␤»