function dlapy2( x, y ) {
	var xabs;
	var yabs;
	var w;
	var z;

	xabs = abs( x );
	yabs = abs( y );

	w = max( xabs, yabs );
	z = min( xabs, yabs );

	if ( z === 0.0 ) {
		return w;
	}
	return w * ( sqrt( 1.0 + abs2( z / w ) ) );
}
Returns `sqrt(x^2 + y^2)` in a manner which doesn't cause unnecessary overflow.

@param {number} x - first input number
@param {number} y - second input number
@returns {number} `sqrt(x^2 + y^2)`

@example
var out = dlapy2( 3.0, 4.0 );
// returns 5.0