function indexed( x, value ) {
	var n;
	var i;

	n = 0;
	for ( i = 0; i < x.length; i++ ) {
		if ( isSameValue( x[ i ], value ) ) {
			n += 1;
		}
	}
	return n;
}
Counts the number of elements in an array that are equal to a specified value.

@private
@param {Collection} x - input array
@param {*} value - search value
@returns {NonNegativeInteger} number of elements that are equal to a specified value

@example
var x = [ 0, 1, 0, 1, 1 ];

var n = indexed( x, 1 );
// returns 3