Note. Perl's definition of "never be reached" is unaware of the possibility of being reached by goto. This is documented, so the following proves your assertion and is not a bug in Perl:

if (0) {
  FOO: {
    print "How many times will I print?\n";
  }
}
goto FOO;
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Note, however, that Perl will parse the code in the commented out section. If this bothers you, you can do arbitrary pre-processing through Filter::Simple. (Note that the inability to parse arbitrary Perl makes this facility substantially less useful than it could be...)