function j0( x ) {
	return addon( x );
}
Computes the Bessel function of the first kind of order zero.

@private
@param {number} x - input value
@returns {number} evaluated Bessel function

@example
var v = j0( 0.0 );
// returns 1.0

@example
var v = j0( 1.0 );
// returns ~0.765

@example
var v = j0( Infinity );
// returns 0.0

@example
var v = j0( -Infinity );
// returns 0.0

@example
var v = j0( NaN );
// returns NaN