Check in codegen test expectations.

test/codegen/expect/language/for_in2_test.js

+dart_library.library('language/for_in2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__for_in2_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const _interceptors = dart_sdk._interceptors;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const for_in2_test = Object.create(null);
+  let SetOfint = () => (SetOfint = dart.constFn(core.Set$(core.int)))();
+  let JSArrayOfint = () => (JSArrayOfint = dart.constFn(_interceptors.JSArray$(core.int)))();
+  let VoidTovoid = () => (VoidTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [])))();
+  dart.defineLazy(for_in2_test, {
+    get set() {
+      return SetOfint().from(JSArrayOfint().of([1, 2]));
+    },
+    set set(_) {}
+  });
+  for_in2_test.x = null;
+  for_in2_test.A = class A extends core.Object {
+    new() {
+      this.field = null;
+    }
+    test() {
+      let count = 0;
+      for (/* Unimplemented unknown name */field of for_in2_test.set) {
+        count = dart.notNull(count) + dart.notNull(core.int._check(this.field));
+      }
+      expect$.Expect.equals(3, count);
+      count = 0;
+      for (/* Unimplemented unknown name */x of for_in2_test.set) {
+        count = dart.notNull(count) + dart.notNull(core.int._check(for_in2_test.x));
+      }
+      expect$.Expect.equals(3, count);
+    }
+  };
+  dart.setSignature(for_in2_test.A, {
+    methods: () => ({test: dart.definiteFunctionType(dart.dynamic, [])})
+  });
+  for_in2_test.main = function() {
+    new for_in2_test.A().test();
+  };
+  dart.fn(for_in2_test.main, VoidTovoid());
+  // Exports:
+  exports.for_in2_test = for_in2_test;
+});