[perl #130439] [REGRESSION] splice no longer attempts to numify things (@a.splice: ^3)

[via RT]

# New Ticket Created by  Aleks-Daniel Jakimenko-Aleksejev 
# Please include the string:  [perl #130439]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=130439 >


Code:
my @a = <a b c d e f g>; say @a.splice: ^3

Result (2015.12,2016.07.1):
[d e f g]

Result (HEAD):
Cannot resolve caller splice(Array: Range); none of these signatures match:
    (Array:D \SELF: *%_)
    (Array:D $: Whatever, *%_)
    (Array:D $: Callable:D $offset, *%_)
    (Array:D $: Int:D $offset, *%_)
    (Array:D $: Whatever, Whatever, *%_)
    (Array:D $: Whatever, Int:D $size, *%_)
    (Array:D $: Whatever, Callable:D $size, *%_)
    (Array:D $: Callable:D $offset, Callable:D $size, *%_)
    (Array:D $: Callable:D $offset, Whatever, *%_)
    (Array:D $: Callable:D $offset, Int:D $size, *%_)
    (Array:D $: Int:D $offset, Whatever, *%_)
    (Array:D $: Int:D $offset, Callable:D $size, *%_)
    (Array:D $: Int:D $offset, Int:D $size, *%_)
    (Array:D $: Whatever $offset, Whatever $size, **@new, *%_)
    (Array:D $: Whatever $offset, Callable:D $size, **@new, *%_)
    (Array:D $: Whatever $offset, Int:D $size, **@new, *%_)
    (Array:D $: Callable:D $offset, Whatever $size, **@new, *%_)
    (Array:D $: Callable:D $offset, Callable:D $size, **@new, *%_)
    (Array:D $: Callable:D $offset, Int:D $size, **@new, *%_)
    (Array:D $: Int:D $offset, Whatever $size, **@new, *%_)
    (Array:D $: Int:D $offset, Callable:D $size, **@new, *%_)
    (Array:D $: Int:D $offset, Int:D $size, **@new, *%_)
    (Array:D $: Whatever, Whatever, @new, *%_)
    (Array:D $: Whatever, Int:D $size, @new, *%_)
    (Array:D $: Whatever, Callable:D $size, @new, *%_)
    (Array:D $: Callable:D $offset, Callable:D $size, @new, *%_)
    (Array:D $: Callable:D $offset, Whatever, @new, *%_)
    (Array:D $: Callable:D $offset, Int:D $size, @new, *%_)
    (Array:D $: Int:D $offset, Whatever, @new, *%_)
    (Array:D $: Int:D $offset, Callable:D $size, @new, *%_)
    (Array:D $: Int:D $offset, Int:D $size, @new, *%_)
in block <unit> at /tmp/SItA2b7BIp line 1


Bisectable points to 
https://github.com/rakudo/rakudo/commit/f32173b2ca3a2652277b81ff381e6377632f0538

Given that the commit was attempting to improve the performance, I think the 
change was unintentional. However, feel free to argue that the current behavior 
is correct. If so, please treat this ticket as [LTA] (the amount of candidates 
printed is insane).