function setArrayLike( arr, idx, value ) {
	arr[ idx ] = value;
}
Sets an element in an indexed array-like object.

@private
@param {Collection} arr - input array
@param {NonNegativeInteger} idx - element index
@param {*} value - value to set

@example
var arr = [ 1, 2, 3, 4 ];

setArrayLike( arr, 2, 3 );

var v = arr[ 2 ];
// returns 3