Rework standalone to use a synchronous loader that does not invoke Dart code

runtime/vm/message_handler.cc

 // Copyright (c) 2011, 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 "vm/message_handler.h"
 
 #include "vm/dart.h"
 #include "vm/lockers.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 439 matching lines @@
   live_ports_--;
 }
 
 
 void MessageHandler::PausedOnStart(bool paused) {
   MonitorLocker ml(&monitor_);
   PausedOnStartLocked(&ml, paused);
 }
 
 
+void MessageHandler::DebugDump() {
+  PortMap::DebugDumpForMessageHandler(this);
+}
+
+
 void MessageHandler::PausedOnStartLocked(MonitorLocker* ml, bool paused) {
   if (paused) {
     ASSERT(!is_paused_on_start_);
     is_paused_on_start_ = true;
     paused_timestamp_ = OS::GetCurrentTimeMillis();
   } else {
     ASSERT(is_paused_on_start_);
     is_paused_on_start_ = false;
     paused_timestamp_ = -1;
   }
@@ skipping 55 matching lines @@
   handler_->oob_message_handling_allowed_ = false;
 }
 
 
 MessageHandler::AcquiredQueues::~AcquiredQueues() {
   ASSERT(handler_ != NULL);
   handler_->oob_message_handling_allowed_ = true;
 }
 
 }  // namespace dart