Removed EnterIsolateIfNeeded and a soon-to-be-useless assertion.

src/isolate.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1653 matching lines @@
   Thread::SetThreadLocal(per_isolate_thread_data_key_, data);
 }
 
 
 Isolate::~Isolate() {
   TRACE_ISOLATE(destructor);
 
   // Has to be called while counters_ are still alive
   runtime_zone_.DeleteKeptSegment();
 
-  // The entry stack must be empty when we get here,
-  // except for the default isolate, where it can
-  // still contain up to one entry stack item
-  ASSERT(entry_stack_ == NULL || this == default_isolate_);
+  // The entry stack must be empty when we get here.
   ASSERT(entry_stack_ == NULL || entry_stack_->previous_item == NULL);
 
   delete entry_stack_;
   entry_stack_ = NULL;
 
   delete[] assembler_spare_buffer_;
   assembler_spare_buffer_ = NULL;
 
   delete unicode_cache_;
   unicode_cache_ = NULL;
@@ skipping 578 matching lines @@
       Handle<JSObject> obj = factory()->NewJSObjectFromMap(map);
       JSObject::NormalizeProperties(obj, KEEP_INOBJECT_PROPERTIES, 8);
       JSObject::SetProperty(registry, name, obj, NONE, STRICT).Assert();
     }
   }
   return Handle<JSObject>::cast(factory()->symbol_registry());
 }
 
 
 } }  // namespace v8::internal