Check in codegen test expectations.

test/codegen/expect/language/enum_index_test.js

Index: test/codegen/expect/language/enum_index_test.js
diff --git a/test/codegen/expect/language/enum_index_test.js b/test/codegen/expect/language/enum_index_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..856c197207734255746d976f6d8602eb53694a7e
--- /dev/null
+++ b/test/codegen/expect/language/enum_index_test.js
@@ -0,0 +1,44 @@
+dart_library.library('language/enum_index_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__enum_index_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 enum_index_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  let dynamicAnddynamicTodynamic = () => (dynamicAnddynamicTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [dart.dynamic, dart.dynamic])))();
+  enum_index_test.Enum = class Enum extends core.Object {
+    new(index) {
+      this.index = index;
+    }
+    toString() {
+      return {
+        0: "Enum.A",
+        1: "Enum.B"
+      }[this.index];
+    }
+  };
+  enum_index_test.Enum.A = dart.const(new enum_index_test.Enum(0));
+  enum_index_test.Enum.B = dart.const(new enum_index_test.Enum(1));
+  enum_index_test.Enum.values = dart.constList([enum_index_test.Enum.A, enum_index_test.Enum.B], enum_index_test.Enum);
+  enum_index_test.Class = class Class extends core.Object {
+    new() {
+      this.index = null;
+    }
+  };
+  enum_index_test.main = function() {
+    enum_index_test.test(null, new enum_index_test.Class());
+    enum_index_test.test(0, enum_index_test.Enum.A);
+    enum_index_test.test(1, enum_index_test.Enum.B);
+  };
+  dart.fn(enum_index_test.main, VoidTodynamic());
+  enum_index_test.test = function(expected, object) {
+    expect$.Expect.equals(expected, dart.dload(object, 'index'));
+  };
+  dart.fn(enum_index_test.test, dynamicAnddynamicTodynamic());
+  // Exports:
+  exports.enum_index_test = enum_index_test;
+});