function dapxsum( N, alpha, x, strideX, offsetX ) {
	return dapxsumkbn( N, alpha, x, strideX, offsetX );
}
Adds a scalar constant to each double-precision floating-point strided array element and computes the sum.

@param {PositiveInteger} N - number of indexed elements
@param {number} alpha - scalar constant
@param {Float64Array} x - input array
@param {integer} strideX - stride length
@param {NonNegativeInteger} offsetX - starting index
@returns {number} sum

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

var x = new Float64Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] );

var v = dapxsum( 4, 5.0, x, 2, 1 );
// returns 25.0