benchmark: remove needless RegExp capturing

Use non-capturing grouping or remove capturing completely when:

* capturing is useless per se, e.g. in test() check;
* captured groups are not used afterwards at all;
* some of the later captured groups are not used afterwards.

PR-URL: https://github.com/nodejs/node/pull/13718
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

benchmark/common.js

@@ -217,7 +217,7 @@ function formatResult(data) {
   }
 
   var rate = data.rate.toString().split('.');
-  rate[0] = rate[0].replace(/(\d)(?=(\d\d\d)+(?!\d))/g, '$1,');
+  rate[0] = rate[0].replace(/(\d)(?=(?:\d\d\d)+(?!\d))/g, '$1,');
   rate = (rate[1] ? rate.join('.') : rate[0]);
   return `${data.name}${conf}: ${rate}`;
 }

benchmark/run.js

@@ -60,7 +60,7 @@ if (format === 'csv') {
       console.log(`"${data.name}", "${conf}", ${data.rate}, ${data.time}`);
     } else {
       var rate = data.rate.toString().split('.');
-      rate[0] = rate[0].replace(/(\d)(?=(\d\d\d)+(?!\d))/g, '$1,');
+      rate[0] = rate[0].replace(/(\d)(?=(?:\d\d\d)+(?!\d))/g, '$1,');
       rate = (rate[1] ? rate.join('.') : rate[0]);
       console.log(`${data.name} ${conf}: ${rate}`);
     }