[perl #130816] assignment silently drops colon list elements

[via RT]

# New Ticket Created by  Wenzel Peppmeyer 
# Please include the string:  [perl #130816]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=130816 >


my $manna = :a1:b2:c3; dd $manna;
# OUTPUT: «Pair $manna = :a1␤»
# expected: warning or error on useless colon pairs

my @manna = :a1:b2:c3; dd @manna;
# OUTPUT: «Array @manna = [:a1]␤»
# expected: this should either just work or warn/error on useless colon pairs