bench: refactor to use dynamic memory allocation in blas/ext/base/dapx

PR-URL: #8646
Ref: #8643
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: iampratik13

lib/node_modules/@stdlib/blas/ext/base/dapx/benchmark/c/benchmark.length.c

@@ -96,10 +96,11 @@ static double rand_double( void ) {
 */
 static double benchmark1( int iterations, int len ) {
 	double elapsed;
-	double x[ len ];
+	double *x;
 	double t;
 	int i;
 
+	x = (double *)malloc( len * sizeof(double) );
 	for ( i = 0; i < len; i++ ) {
 		x[ i ] = ( rand_double()*200.0 ) - 100.0;
 	}
@@ -116,15 +117,17 @@ static double benchmark1( int iterations, int len ) {
 	if ( x[ 0 ] != x[ 0 ] ) {
 		printf( "should not return NaN\n" );
 	}
+	free( x );
 	return elapsed;
 }
 
 static double benchmark2( int iterations, int len ) {
 	double elapsed;
-	double x[ len ];
+	double *x;
 	double t;
 	int i;
 
+	x = (double *)malloc( len * sizeof(double) );
 	for ( i = 0; i < len; i++ ) {
 		x[ i ] = ( rand_double()*200.0 ) - 100.0;
 	}
@@ -141,6 +144,7 @@ static double benchmark2( int iterations, int len ) {
 	if ( x[ 0 ] != x[ 0 ] ) {
 		printf( "should not return NaN\n" );
 	}
+	free( x );
 	return elapsed;
 }