[test/inspector] remove any usage of v8::Extension

test/inspector/debugger/collect-old-async-call-chains.js

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 InspectorTest.log('Checks that we drop old async call chains.');
 
 Protocol.Debugger.enable();
 Protocol.Runtime.enable();
 InspectorTest.runAsyncTestSuite([
   async function testInfrastructure() {
@@ skipping 147 matching lines @@
   let stackTrace = message.params.asyncStackTrace || message.params.stackTrace.parent;
   let asyncChainCount = 0;
   while (stackTrace) {
     ++asyncChainCount;
     stackTrace = stackTrace.parent;
   }
   InspectorTest.log(`actual async chain len: ${asyncChainCount}\n`);
 }
 
 async function setMaxAsyncTaskStacks(max) {
-  let expression = `setMaxAsyncTaskStacks(${max})`;
+  let expression = `inspector.setMaxAsyncTaskStacks(${max})`;
   InspectorTest.log(expression);
   await Protocol.Runtime.evaluate({expression});
 }