benchmark: remove deprecated _extend from benchmark

Author: RafaelGSS

benchmark/es/spread-assign.js

@@ -1,15 +1,15 @@
 'use strict';
 
 const common = require('../common.js');
-const util = require('util');
+const assert = require('node:assert');
 
 const bench = common.createBenchmark(main, {
-  method: ['spread', 'assign', '_extend'],
+  method: ['spread', 'assign'],
   count: [5, 10, 20],
   n: [1e6],
 });
 
-function main({ n, context, count, rest, method }) {
+function main({ n, count, method }) {
 
   const src = {};
   for (let n = 0; n < count; n++)
@@ -18,12 +18,6 @@ function main({ n, context, count, rest, method }) {
   let obj;
 
   switch (method) {
-    case '_extend':
-      bench.start();
-      for (let i = 0; i < n; i++)
-        obj = util._extend({}, src);
-      bench.end(n);
-      break;
     case 'assign':
       bench.start();
       for (let i = 0; i < n; i++)
@@ -39,4 +33,5 @@ function main({ n, context, count, rest, method }) {
     default:
       throw new Error('Unexpected method');
   }
+  assert.ok(obj);
 }