VM: Prohibit reload when throwing or processing language errors.

runtime/vm/isolate.cc

 // 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.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 634 matching lines @@
     if (!unwind.is_user_initiated()) {
       return MessageHandler::kShutdown;
     }
   }
   return MessageHandler::kError;
 }
 
 
 MessageHandler::MessageStatus IsolateMessageHandler::ProcessUnhandledException(
     const Error& result) {
+  NoReloadScope no_reload_scope(T->isolate(), T);
   // Generate the error and stacktrace strings for the error message.
   String& exc_str = String::Handle(T->zone());
   String& stacktrace_str = String::Handle(T->zone());
   if (result.IsUnhandledException()) {
     Zone* zone = T->zone();
     const UnhandledException& uhe = UnhandledException::Cast(result);
     const Instance& exception = Instance::Handle(zone, uhe.exception());
     Object& tmp = Object::Handle(zone);
     tmp = DartLibraryCalls::ToString(exception);
     if (!tmp.IsString()) {
@@ skipping 2280 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart