Check in codegen test expectations.

test/codegen/expect/language/regress_22728_test.js

+dart_library.library('language/regress_22728_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__regress_22728_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 regress_22728_test = Object.create(null);
+  let VoidTobool = () => (VoidTobool = dart.constFn(dart.definiteFunctionType(core.bool, [])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  regress_22728_test.assertsChecked = function() {
+    let checked = false;
+    try {
+      dart.assert(false);
+    } catch (error) {
+      if (core.AssertionError.is(error)) {
+        checked = true;
+      } else
+        throw error;
+    }
+
+    return checked;
+  };
+  dart.fn(regress_22728_test.assertsChecked, VoidTobool());
+  regress_22728_test.main = function() {
+    return dart.async(function*() {
+      let fault = false;
+      try {
+        dart.assert(yield false);
+      } catch (error) {
+        if (core.AssertionError.is(error)) {
+          fault = true;
+        } else
+          throw error;
+      }
+
+      expect$.Expect.equals(regress_22728_test.assertsChecked(), fault);
+    }, dart.dynamic);
+  };
+  dart.fn(regress_22728_test.main, VoidTodynamic());
+  // Exports:
+  exports.regress_22728_test = regress_22728_test;
+});