[perl #131686] [BUG] [X] @list-of-lists misbehaves with list of one list

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# New Ticket Created by  Michael Schaap 
# Please include the string:  [perl #131686]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=131686 >


This is OK:

 > say [X] ((1,2,3), (4,5,6));
((1 4) (1 5) (1 6) (2 4) (2 5) (2 6) (3 4) (3 5) (3 6))
 > say [X*] ((1,2,3), (4,5,6));
(4 5 6 8 10 12 12 15 18)

... but this is incorrect:

 > say [X] ((1,2,3),);
((1 2 3))
 > say [X*] ((1,2,3),);
(6)

Expected output is:
((1) (2) (3))
and
((1) (2) (3))


Note that [*] behaves as expected:

 > say [*] ((1,2,3),(4,5,6));
9
 > say [*] ((1,2,3),);
3

... since this is equivalent to:

 > say [*] (3, 3);
9
 > say [*] (3,);
3