array_shuffle() for GameMaker Studio 2.3.1

array_shuffle.gml

// Adds to GMS2.3.1's new "array_" functions.
// Based of Fisher-Yates Shuffle https://bost.ocks.org/mike/shuffle/
function array_shuffle(_array) {
	var _len = array_length(_array), _last = 0, _i = 0;
	while(_len) {
		_i = irandom(--_len);
		_last = _array[_len];
		_array[_len] = _array[_i];
		_array[_i] = _last;
	}
	return _array;
}