for my $y ( ... ) {
   for my $x ( ... ) {
      next;
   }
}

##</code><code>##

Y: for my $y ( ... ) {
   X: for my $x ( ... ) {
      next X;
   }
}

##</code><code>##

Y: for my $y ( ... ) {
   X: for my $x ( ... ) {
      next Y;
   }
}

##</code><code>##

for ( @a ) {
   {
      last;
   }
   say;
}

##</code><code>##

for ( @a ) {
   say;
}