Check in codegen test expectations.

test/codegen/expect/language/compile_time_constant_n_test.js

+dart_library.library('language/compile_time_constant_n_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__compile_time_constant_n_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 compile_time_constant_n_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  compile_time_constant_n_test.A = class A extends core.Object {
+    new() {
+    }
+    ['=='](x) {
+      return dart.equals(x, 499);
+    }
+  };
+  dart.setSignature(compile_time_constant_n_test.A, {
+    constructors: () => ({new: dart.definiteFunctionType(compile_time_constant_n_test.A, [])})
+  });
+  compile_time_constant_n_test.a = dart.const(new compile_time_constant_n_test.A());
+  let const$;
+  compile_time_constant_n_test.main = function() {
+    if (!dart.equals(const$ || (const$ = dart.const(new compile_time_constant_n_test.A())), 499)) expect$.Expect.isTrue("const equality failed");
+    expect$.Expect.isTrue(dart.equals(compile_time_constant_n_test.a, 499));
+  };
+  dart.fn(compile_time_constant_n_test.main, VoidTodynamic());
+  // Exports:
+  exports.compile_time_constant_n_test = compile_time_constant_n_test;
+});