Check in codegen test expectations.

test/codegen/expect/language/issue21957_test.js

+dart_library.library('language/issue21957_test', null, /* Imports */[
+  'dart_sdk'
+], function load__issue21957_test(exports, dart_sdk) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const issue21957_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  issue21957_test.main = function() {
+    for (let i = 0; i < 1000000; i++) {
+      new issue21957_test.A();
+    }
+  };
+  dart.fn(issue21957_test.main, VoidTodynamic());
+  issue21957_test.A = class A extends core.Object {
+    new() {
+      this.a = 1.0;
+    }
+  };
+  // Exports:
+  exports.issue21957_test = issue21957_test;
+});