Check in codegen test expectations.

test/codegen/expect/language/null_is2_test.js

Index: test/codegen/expect/language/null_is2_test.js
diff --git a/test/codegen/expect/language/null_is2_test.js b/test/codegen/expect/language/null_is2_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..6d2a5a8394a8bdcceeb646b08d36ab0ef35f0583
--- /dev/null
+++ b/test/codegen/expect/language/null_is2_test.js
@@ -0,0 +1,38 @@
+dart_library.library('language/null_is2_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__null_is2_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const null_is2_test = Object.create(null);
+  let Test = () => (Test = dart.constFn(null_is2_test.Test$()))();
+  let TestOfObject = () => (TestOfObject = dart.constFn(null_is2_test.Test$(core.Object)))();
+  let TestOfint = () => (TestOfint = dart.constFn(null_is2_test.Test$(core.int)))();
+  let ListOfObject = () => (ListOfObject = dart.constFn(core.List$(core.Object)))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  null_is2_test.Test$ = dart.generic(T => {
+    class Test extends core.Object {
+      foo(a) {
+        return T.is(a);
+      }
+    }
+    dart.addTypeTests(Test);
+    dart.setSignature(Test, {
+      methods: () => ({foo: dart.definiteFunctionType(dart.dynamic, [dart.dynamic])})
+    });
+    return Test;
+  });
+  null_is2_test.Test = Test();
+  null_is2_test.main = function() {
+    expect$.Expect.isTrue(new (TestOfObject())().foo(null));
+    expect$.Expect.isTrue(new null_is2_test.Test().foo(null));
+    expect$.Expect.isFalse(new (TestOfint())().foo(null));
+    expect$.Expect.isFalse(ListOfObject().is(null));
+  };
+  dart.fn(null_is2_test.main, VoidTodynamic());
+  // Exports:
+  exports.null_is2_test = null_is2_test;
+});