1. Restructure reusable handles to make individual Scopes for each handle type

runtime/vm/longjump.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/longjump.h"
 
 #include "include/dart_api.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/isolate.h"
@@ skipping 26 matching lines @@
 
 
 void LongJumpScope::Jump(int value, const Error& error) {
   // A zero is the default return value from setting up a LongJumpScope
   // using Set.
   ASSERT(value != 0);
   ASSERT(IsSafeToJump());
 
   Isolate* isolate = Isolate::Current();
 
+#if defined(DEBUG)
+#define CHECK_REUSABLE_HANDLE(name)                                            \
+  ASSERT(!isolate->reusable_##name##_handle_scope_active());
+REUSABLE_HANDLE_LIST(CHECK_REUSABLE_HANDLE)
+#undef CHECK_REUSABLE_HANDLE
+#endif  // defined(DEBUG)
+
   // Remember the error in the sticky error of this isolate.
   isolate->object_store()->set_sticky_error(error);
 
   // Destruct all the active StackResource objects.
   StackResource* current_resource = isolate->top_resource();
   while (current_resource != top_) {
     current_resource->~StackResource();
     current_resource = isolate->top_resource();
   }
   longjmp(environment_, value);
   UNREACHABLE();
 }
 
 }  // namespace dart