[perl #129780] [BUG] no error about double closure when there are multiple *s in a where clause

[via RT]

# New Ticket Created by  Daniel Green 
# Please include the string:  [perl #129780]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=129780 >


perl6 -e 'sub foo($a where {* < 5}) { dd $a }; foo(3);'
===SORRY!=== Error while compiling -e
Malformed double closure; WhateverCode is already a closure without
curlies, so either remove the curlies or use valid parameter syntax instead
of *
at -e:1
------> sub foo($a where {* < 5}⏏) { dd $a }; foo(3);
    expecting any of:
        horizontal whitespace
        statement end
        statement modifier
        statement modifier loop

but

perl6 -e 'sub foo($a where {* < 5 and * > 9}) { dd $a }; foo(3);'
Int $a = 3

There's no error and the (impossible) where clause is ignored.