[perl #128017] enum treats a Seq of Pairs as a List of Str

[via RT]

# New Ticket Created by  Wenzel Peppmeyer 
# Please include the string:  [perl #128017]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=128017 >


enum Bits ( (('Bit-' X~ 1..8) Z=> (1, 2, 4 ... 256)) ); dd Bits.enums;
# OUTPUT«{"Bit-1\t1" => 0, "Bit-2\t2" => 1, "Bit-3\t4" => 2, "Bit-4\t8" => 3, 
"Bit-5\t16" => 4, "Bit-6\t32" => 5, "Bit-7\t64" => 6, "Bit-8\t128" => 7}␤»

# expected:
# OUTPUT«{"Bit-1" => 1, "Bit-2" => 2, "Bit-3" => 4, "Bit-4" => 8, "Bit-5" => 
16, "Bit-6" => 32, "Bit-7" => 64, "Bit-8" => 128}␤»