List interpolation

Scalar arrays do not interpolate:

my @x = 1,2,3;
my $y = @x;

say @x.elems;                 # 3
for @x { print "loop", $_ }   # "loop1loop2loop3"

say $y.elems;                 # 3
for $y { print "loop", $_ }   # "loop1 2 3"