> perl -MO=Deparse -E'if (1) { label: say 1;}; goto label'
BEGIN {
    $^H{'feature_say'} = q(1);
    $^H{'feature_state'} = q(1);
    $^H{'feature_switch'} = q(1);
}
do {
    label: say 1
};
goto label;

##</code><code>##

perl -wE'do { label: say 1;}; goto label'

##</code><code>##

perl -wE'my $x=0;do { label: say $x++; die if $x>1}; goto label'
0
1
Died at -e line 1.

##</code><code>##

[davido]: LanX: perl -E 'goto IN; do{ IN: say "Hello world\n";};' does produce the warning on 5.16.2.