Move Null class out of the VM isolate.

runtime/vm/dart_api_impl_test.cc

 // Copyright (c) 2012, 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.
 
 #include "bin/builtin.h"
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/json.h"
@@ skipping 185 matching lines @@
   // Equal objects.
   EXPECT(!Dart_IdentityEquals(five, five_again));
 
   // Different objects.
   EXPECT(!Dart_IdentityEquals(five, seven));
 
   // Non-instance objects.
   {
     Isolate* isolate = Isolate::Current();
     DARTSCOPE(isolate);
-    Dart_Handle class1 = Api::NewHandle(isolate, Object::null_class());
+    Dart_Handle class1 = Api::NewHandle(isolate, Object::void_class());
     Dart_Handle class2 = Api::NewHandle(isolate, Object::class_class());
 
     EXPECT(Dart_IdentityEquals(class1, class1));
 
     EXPECT(!Dart_IdentityEquals(class1, class2));
   }
 }
 
 
 TEST_CASE(ObjectEquals) {
@@ skipping 7026 matching lines @@
                                    NewString("main"),
                                    0,
                                    NULL);
   int64_t value = 0;
   result = Dart_IntegerToInt64(result, &value);
   EXPECT_VALID(result);
   EXPECT_EQ(8, value);
 }
 
 }  // namespace dart