function rcbrt( x ) {
	return addon( x );
}
Computes the reciprocal cube root of a double-precision floating-point number.

@private
@param {number} x - input value
@returns {number} reciprocal cube root

@example
var v = rcbrt( 8.0 );
// returns 0.5

@example
var v = rcbrt( 1000.0 );
// returns 0.1

@example
var v = rcbrt( 0.0 );
// returns Infinity

@example
var v = rcbrt( Infinity );
// returns 0.0

@example
var v = rcbrt( -8.0 );
// returns -0.5

@example
var v = rcbrt( NaN );
// returns NaN