function sincos( x ) {
	var out = new Float64Array( 2 );
	addon( x, out );
	return out;
}
Simultaneously computes the sine and cosine of an angle measured in radians.

@private
@param {number} x - input value (in radians)
@returns {Array<number>} sine and cosine

@example
var v = sincos( 0.0 );
// returns <Float64Array>[ ~0.0, ~1.0 ]

@example
var v = sincos( 3.141592653589793 / 2.0 );
// returns <Float64Array>[ ~1.0, ~0.0 ]

@example
var v = sincos( -3.141592653589793 / 6.0 );
// returns <Float64Array>[ ~-0.5, ~0.866 ]

@example
var v = sincos( NaN );
// returns <Float64Array>[ NaN, NaN ]