function dfill( N, alpha, x, strideX ) {
	return ndarray( N, alpha, x, strideX, stride2offset( N, strideX ) );
}
Fills a double-precision floating-point strided array with a specified scalar constant.

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

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

var x = new Float64Array( [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0 ] );

dfill( x.length, 5.0, x, 1 );
// x => <Float64Array>[ 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0, 5.0 ]