Move Null class out of the VM isolate.

runtime/vm/snapshot_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 "include/dart_debugger_api.h"
 #include "platform/assert.h"
 #include "vm/bigint_operations.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_message.h"
@@ skipping 442 matching lines @@
   CheckBigint("-0x11111111111111111111");
   CheckBigint("0x9876543210987654321098765432109876543210");
   CheckBigint("-0x9876543210987654321098765432109876543210");
 }
 
 TEST_CASE(SerializeSingletons) {
   // Write snapshot with object content.
   uint8_t* buffer;
   MessageWriter writer(&buffer, &malloc_allocator);
   writer.WriteObject(Object::class_class());
-  writer.WriteObject(Object::null_class());
   writer.WriteObject(Object::type_arguments_class());
   writer.WriteObject(Object::instantiated_type_arguments_class());
   writer.WriteObject(Object::function_class());
   writer.WriteObject(Object::field_class());
   writer.WriteObject(Object::token_stream_class());
   writer.WriteObject(Object::script_class());
   writer.WriteObject(Object::library_class());
   writer.WriteObject(Object::code_class());
   writer.WriteObject(Object::instructions_class());
   writer.WriteObject(Object::pc_descriptors_class());
   writer.WriteObject(Object::exception_handlers_class());
   writer.WriteObject(Object::context_class());
   writer.WriteObject(Object::context_scope_class());
   intptr_t buffer_len = writer.BytesWritten();
 
   // Read object back from the snapshot.
   SnapshotReader reader(buffer, buffer_len, Snapshot::kMessage,
                         Isolate::Current());
   EXPECT(Object::class_class() == reader.ReadObject());
-  EXPECT(Object::null_class() == reader.ReadObject());
   EXPECT(Object::type_arguments_class() == reader.ReadObject());
   EXPECT(Object::instantiated_type_arguments_class() == reader.ReadObject());
   EXPECT(Object::function_class() == reader.ReadObject());
   EXPECT(Object::field_class() == reader.ReadObject());
   EXPECT(Object::token_stream_class() == reader.ReadObject());
   EXPECT(Object::script_class() == reader.ReadObject());
   EXPECT(Object::library_class() == reader.ReadObject());
   EXPECT(Object::code_class() == reader.ReadObject());
   EXPECT(Object::instructions_class() == reader.ReadObject());
   EXPECT(Object::pc_descriptors_class() == reader.ReadObject());
@@ skipping 1998 matching lines @@
   result = Dart_RunLoop();
   EXPECT(Dart_IsError(result));
   EXPECT(Dart_ErrorHasException(result));
   EXPECT_SUBSTRING("Exception: nulltruefalse123456æøå3.14[]100123456789\n",
                    Dart_GetError(result));
 
   Dart_ExitScope();
 }
 
 }  // namespace dart