Check in codegen test expectations.

test/codegen/expect/language/async_await_syntax_test_b12g_multi.js

+dart_library.library('language/async_await_syntax_test_b12g_multi', null, /* Imports */[
+  'dart_sdk'
+], function load__async_await_syntax_test_b12g_multi(exports, dart_sdk) {
+  'use strict';
+  const core = dart_sdk.core;
+  const async = dart_sdk.async;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const async_await_syntax_test_b12g_multi = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  let VoidTovoid = () => (VoidTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [])))();
+  async_await_syntax_test_b12g_multi.yield = 0;
+  async_await_syntax_test_b12g_multi.await = 0;
+  dart.copyProperties(async_await_syntax_test_b12g_multi, {
+    get st() {
+      return async.Stream.fromIterable([]);
+    }
+  });
+  async_await_syntax_test_b12g_multi.B = class B extends core.Object {};
+  async_await_syntax_test_b12g_multi.C = class C extends async_await_syntax_test_b12g_multi.B {
+    new() {
+    }
+    get b12g() {
+      return dart.async(function*() {
+        return null;
+      }, dart.dynamic);
+    }
+  };
+  dart.setSignature(async_await_syntax_test_b12g_multi.C, {
+    constructors: () => ({new: dart.definiteFunctionType(async_await_syntax_test_b12g_multi.C, [])})
+  });
+  async_await_syntax_test_b12g_multi.method1 = function() {
+  };
+  dart.fn(async_await_syntax_test_b12g_multi.method1, VoidTodynamic());
+  async_await_syntax_test_b12g_multi.method2 = function() {
+  };
+  dart.fn(async_await_syntax_test_b12g_multi.method2, VoidTodynamic());
+  async_await_syntax_test_b12g_multi.main = function() {
+    let a = null;
+    let c = new async_await_syntax_test_b12g_multi.C();
+    a = c.b12g;
+    async_await_syntax_test_b12g_multi.method1();
+    async_await_syntax_test_b12g_multi.method2();
+  };
+  dart.fn(async_await_syntax_test_b12g_multi.main, VoidTovoid());
+  // Exports:
+  exports.async_await_syntax_test_b12g_multi = async_await_syntax_test_b12g_multi;
+});