[perl #125408] [BUG] CArray[num64] numiness optimised away

[via RT]

# New Ticket Created by  Jonathan Stowe 
# Please include the string:  [perl #125408]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=125408 >


Hi,
The following code gives rise to:

Wrong kind of access to numeric CArray
  in method ASSIGN-POS at lib/NativeCall.pm:333
  in block  at tp:22

In this case it always appears after the 57th item and only when the array is 
in the third generation as here, it does not appear with MVM_SPESH_DISABLE=1 
which lrads me to believe it is something the optimiser is doing.

I think nine did a simple bisect and located it to a few weeks ago.

use v6;

use NativeCall;

my @buff := CArray[num64].new;

my @in = (^100).map({Num($_)});

for ^100 -> $i {
    @buff[$i] = @in[$i];
}

my @in2;

for ^100 -> $i {
    @in2[$i] = @buff[$i];
}

my @buff2 := CArray[num64].new;

for ^100 -> $i {
    @buff2[$i] = @in2[$i];
}