bench: refactor to use dynamic memory allocation in strided/base/zmap

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: na
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: passed
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: passed
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: anandkaranubc

lib/node_modules/@stdlib/strided/base/zmap/benchmark/c/benchmark.length.c

@@ -106,12 +106,14 @@ static double complex identity( const double complex x ) {
 * @return             elapsed time in seconds
 */
 static double benchmark( int iterations, int len ) {
-	double complex x[ len ];
-	double complex y[ len ];
+	double complex *x;
+	double complex *y;
 	double elapsed;
 	double t;
 	int i;
 
+	x = (double complex *)malloc( len * sizeof( double complex ) );
+	y = (double complex *)malloc( len * sizeof( double complex ) );
 	for ( i = 0; i < len; i++ ) {
 		x[ i ] = ( ( rand_double()*200.0 ) - 100.0 ) + ( ( rand_double()*200.0 ) - 100.0 )*I;
 		y[ i ] = 0.0 + 0.0*I;
@@ -129,6 +131,8 @@ static double benchmark( int iterations, int len ) {
 	if ( y[ i%len ] != y[ i%len ] ) {
 		printf( "should not return NaN\n" );
 	}
+	free( x );
+	free( y );
 	return elapsed;
 }