No Gcd Wow 335 Repack

If you download a random "No GCD 335 repack" from AC-Web, EmuCoach, or a Russian forum, how does it actually work under the hood?

// No GCD mod: // if (GetGlobalCooldown() > 0) return SPELL_FAILED_NOT_READY; // Commented out. All spells always ready. no gcd wow 335 repack