Check in codegen test expectations.

test/codegen/expect/language/runtime_type_test.js

Index: test/codegen/expect/language/runtime_type_test.js
diff --git a/test/codegen/expect/language/runtime_type_test.js b/test/codegen/expect/language/runtime_type_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..1033f649c0c141a1d4c16775e302040426c5bf31
--- /dev/null
+++ b/test/codegen/expect/language/runtime_type_test.js
@@ -0,0 +1,25 @@
+dart_library.library('language/runtime_type_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__runtime_type_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 runtime_type_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  runtime_type_test.A = class A extends core.Object {
+    get className() {
+      return this.runtimeType;
+    }
+  };
+  runtime_type_test.main = function() {
+    expect$.Expect.isTrue(core.Type.is(new runtime_type_test.A().className));
+    expect$.Expect.isTrue(core.Type.is(dart.runtimeType(null)));
+    expect$.Expect.equals(dart.runtimeType(null), dart.wrapType(core.Null));
+  };
+  dart.fn(runtime_type_test.main, VoidTodynamic());
+  // Exports:
+  exports.runtime_type_test = runtime_type_test;
+});