Check in codegen test expectations.

test/codegen/expect/corelib/hash_map_test.js

Index: test/codegen/expect/corelib/hash_map_test.js
diff --git a/test/codegen/expect/corelib/hash_map_test.js b/test/codegen/expect/corelib/hash_map_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..c319a6f62972a61d0f1a93b05998d0cc4dbcbbe4
--- /dev/null
+++ b/test/codegen/expect/corelib/hash_map_test.js
@@ -0,0 +1,33 @@
+dart_library.library('corelib/hash_map_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__hash_map_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 hash_map_test = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  hash_map_test.HashMapTest = class HashMapTest extends core.Object {
+    static testMain() {
+      let m = core.Map.new();
+      expect$.Expect.equals(0, m[dartx.length]);
+      expect$.Expect.equals(true, m[dartx.isEmpty]);
+      m[dartx.set]("one", 1);
+      expect$.Expect.equals(1, m[dartx.length]);
+      expect$.Expect.equals(false, m[dartx.isEmpty]);
+      expect$.Expect.equals(1, m[dartx.get]("one"));
+    }
+  };
+  dart.setSignature(hash_map_test.HashMapTest, {
+    statics: () => ({testMain: dart.definiteFunctionType(dart.dynamic, [])}),
+    names: ['testMain']
+  });
+  hash_map_test.main = function() {
+    hash_map_test.HashMapTest.testMain();
+  };
+  dart.fn(hash_map_test.main, VoidTodynamic());
+  // Exports:
+  exports.hash_map_test = hash_map_test;
+});