P+ - Ice Climbers - Common Subroutine 0x80546ea8

1. CreateInterrupt { interrupt_id: None, action: DownAttack, requirement: (ButtonPress value(1)) }
2. PreviousInterruptAddRequirement(OnGround)
3. CreateInterrupt { interrupt_id: None, action: DownStand, requirement: (ShieldInputPress) }
4. PreviousInterruptAddRequirement(OnGround)
5. Return