int main() {
  // Issue: 3: error: empty character constant
  '';

  // Issue: 6: error: multiple characters in character constant
  'ab';
}

int main() {
  // Issue: 3: error: empty character constant
  '';

  // Issue: 6: error: multiple characters in character constant
  'ab';

  // Issue: 9: error: multiple characters in character constant
  '/*';
}

Add character string comment test
Add character string comment test
