function dnrm2( N, x, stride ) {
	return addon( N, x, stride );
}
Computes the L2-norm of a double-precision floating-point vector.

@param {PositiveInteger} N - number of indexed elements
@param {Float64Array} x - input array
@param {integer} stride - stride length
@returns {number} L2-norm

@example
var Float64Array = require( '@stdlib/array/float64' );

var x = new Float64Array( [ 1.0, -2.0, 2.0 ] );

var z = dnrm2( 3, x, 1 );
// returns 3.0