function sliceStart( slice, strides, offset ) {
	var data;
	var idx;
	var i;

	data = slice.data;
	idx = offset;
	for ( i = 0; i < data.length; i++ ) {
		idx += strides[ i ] * data[ i ].start;
	}
	return idx;
}
Resolves the index offset of the first element indexed by a normalized multi-slice.

@private
@param {MultiSlice} slice - normalized multi-slice object
@param {IntegerArray} strides - array strides
@param {NonNegativeInteger} offset - array index offset
@returns {NonNegativeInteger} index offset of the first element indexed by a normalized multi-slice object