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

test/inspector/debugger/inspector-break-api.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 breakProgram,(schedule|cancel)PauseOnNextStatement test API");
 
 InspectorTest.addScript(`
 function callBreakProgram() {
-  breakProgram('reason', JSON.stringify({a: 42}));
+  inspector.breakProgram('reason', JSON.stringify({a: 42}));
 }
 
 function foo() {
   return 42;
 }`, 7, 26);
 
 InspectorTest.setupScriptMap();
 Protocol.Debugger.onPaused(message => {
   InspectorTest.log('Stack:');
   InspectorTest.logCallFrames(message.params.callFrames);
@@ skipping 21 matching lines @@
       .then(next);
   },
 
   function testCancelPauseOnNextStatement(next) {
     utils.schedulePauseOnNextStatement('reason', JSON.stringify({a: 42}));
     utils.cancelPauseOnNextStatement();
     Protocol.Runtime.evaluate({ expression: 'foo()'})
       .then(next);
   }
 ]);