confirm the change fixes nodejs#43129

test/parallel/test-vm-not-strict.js

@@ -0,0 +1,30 @@
+/* eslint-disable strict, no-var, no-delete-var */
+// Related to bug report: https://github.com/nodejs/node/issues/43129
+require('../common');
+var assert = require('assert');
+var vm = require('vm');
+
+var data = [];
+var a = 'direct';
+delete a;
+data.push(a);
+
+var item2 = vm.runInThisContext(`
+var data = [];
+var b = "this";
+delete b;
+data.push(b);
+data[0]
+`);
+data.push(item2);
+
+vm.runInContext(
+  `
+var c = "new";
+delete c;
+data.push(c);
+`,
+  vm.createContext({ data: data })
+);
+
+assert.deepStrictEqual(data, ['direct', 'this', 'new']);