sdl2 :: Mix :: reserve_channels
num channels from being used by play_channel(-1...)Returns the number of of channels reserved.
	# Reserve `num` channels from being used by `play_channel(-1...)`
	#
	# Returns the number of of channels reserved.
	fun reserve_channels(num: Int): Int `{
		return Mix_ReserveChannels(num);
	`}
					lib/sdl2/mixer.nit:126,2--131,3