[perl #127756] setelems on native arrays doesn't clear the array

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# New Ticket Created by  Elizabeth Mattijsen 
# Please include the string:  [perl #127756]
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# <URL: https://rt.perl.org/Ticket/Display.html?id=127756 >


use nqp; my str @a = "a".."e"; nqp::setelems(@a,0); nqp::setelems(@a,5); say 
@a.join(":”)
a:b:c:d:e

expected:
::::


same for int / num arrays.