Check in codegen test expectations.

test/codegen/expect/language/async_star_regression_2238_test.js

Index: test/codegen/expect/language/async_star_regression_2238_test.js
diff --git a/test/codegen/expect/language/async_star_regression_2238_test.js b/test/codegen/expect/language/async_star_regression_2238_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..0a4ef08ffa1d026173b386e2291365b85d39626e
--- /dev/null
+++ b/test/codegen/expect/language/async_star_regression_2238_test.js
@@ -0,0 +1,37 @@
+dart_library.library('language/async_star_regression_2238_test', null, /* Imports */[
+  'dart_sdk',
+  'async_helper',
+  'expect'
+], function load__async_star_regression_2238_test(exports, dart_sdk, async_helper, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const _interceptors = dart_sdk._interceptors;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const async_helper$ = async_helper.async_helper;
+  const expect$ = expect.expect;
+  const async_star_regression_2238_test = Object.create(null);
+  let JSArrayOfint = () => (JSArrayOfint = dart.constFn(_interceptors.JSArray$(core.int)))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  let dynamicTodynamic = () => (dynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic])))();
+  async_star_regression_2238_test.main = function() {
+    function f() {
+      return dart.asyncStar(function*(stream) {
+        label1:
+          label2: {
+            if (stream.add(0)) return;
+            yield;
+          }
+      }, dart.dynamic);
+    }
+    dart.fn(f, VoidTodynamic());
+    async_helper$.asyncStart();
+    dart.dsend(dart.dsend(f(), 'toList'), 'then', dart.fn(list => {
+      expect$.Expect.listEquals(JSArrayOfint().of([0]), core.List._check(list));
+      async_helper$.asyncEnd();
+    }, dynamicTodynamic()));
+  };
+  dart.fn(async_star_regression_2238_test.main, VoidTodynamic());
+  // Exports:
+  exports.async_star_regression_2238_test = async_star_regression_2238_test;
+});