function rad2degf( x ) {
	return addon( x );
}
Converts an angle from radians to degrees (single-precision).

@private
@param {number} x - angle in radians
@returns {number} angle in degrees

@example
var d = rad2degf( 3.141592653589793 / 2.0 );
// returns 90.0

@example
var d = rad2degf( -3.141592653589793 / 4.0 );
// returns -45.0

@example
var d = rad2degf( NaN );
// returns NaN