Runtime fixes on DDC tests

pkg/dev_compiler/test/codegen/language/map_literal5_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Test the use of general expression as keys in map literals.
 
 library map_literal5_test;
 
 import "package:expect/expect.dart";
 
@@ skipping 14 matching lines @@
     Expect.equals(0, m[true]);
     Expect.equals(3, m[2]);
     Expect.equals(2, m[1]);
   } else {
     Expect.equals(0, m[false]);
     Expect.equals("baz", m["bar"]);
     Expect.equals(2, m["foo"]);
   }
 }
 
-create(bool b) {
+Map create(bool b) {
   return {
     b: 0,
     m(b): n(b),
     b ? 1 : "foo": 2,
   };
 }
 
-m(bool b) => b ? 2 : "bar";
-n(bool b) => b ? 3 : "baz";
+Object m(bool b) => b ? 2 : "bar";
+Object n(bool b) => b ? 3 : "baz";