Add stub versions of KernelInferrerEngine and friends

tests/compiler/dart2js/simple_inferrer_callers_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Test that computation of callers of an element works when two
 // elements of the same name are being invoked in the same method.
 
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/common_elements.dart';
@@ skipping 12 matching lines @@
 }
 
 main() {
   new A().field;
   new B().field;
 }
 """;
 
 // Create our own type inferrer to avoid clearing out the internal
 // data structures.
-class MyInferrer extends TypeGraphInferrer {
+class MyInferrer extends AstTypeGraphInferrer {
   MyInferrer(compiler, closedWorld, closedWorldRefiner)
       : super(compiler, closedWorld, closedWorldRefiner);
   clear() {}
 }
 
 void main() {
   Uri uri = new Uri(scheme: 'source');
   var compiler = compilerFor(TEST, uri, analyzeOnly: true);
   asyncTest(() => compiler.run(uri).then((_) {
         ElementEnvironment elementEnvironment =
@@ skipping 12 matching lines @@
         var mainElement = findElement(compiler, 'main');
         dynamic classA = findElement(compiler, 'A');
         var fieldA = classA.lookupLocalMember('field');
         dynamic classB = findElement(compiler, 'B');
         var fieldB = classB.lookupLocalMember('field');
 
         Expect.isTrue(inferrer.getCallersOf(fieldA).contains(mainElement));
         Expect.isTrue(inferrer.getCallersOf(fieldB).contains(mainElement));
       }));
 }