Add defensive assert for having a weak, empty presistent in a

src/global-handles.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "v8.h"
 
 #include "api.h"
 #include "global-handles.h"
 
 #include "vm-state-inl.h"
@@ skipping 189 matching lines @@
     return parameter_or_next_free_.next_free;
   }
   void set_next_free(Node* value) {
     ASSERT(state() == FREE);
     parameter_or_next_free_.next_free = value;
   }
 
   void MakeWeak(void* parameter, WeakCallback weak_callback) {
     ASSERT(weak_callback != NULL);
     ASSERT(state() != FREE);
+    CHECK(object_ != NULL);
     set_state(WEAK);
     set_parameter(parameter);
     weak_callback_ = weak_callback;
   }
 
   void* ClearWeakness() {
     ASSERT(state() != FREE);
     void* p = parameter();
     set_state(NORMAL);
     set_parameter(NULL);
@@ skipping 843 matching lines @@
   ASSERT_EQ(isolate->heap()->the_hole_value(), blocks_[block][offset]);
   blocks_[block][offset] = object;
   if (isolate->heap()->InNewSpace(object)) {
     new_space_indices_.Add(size_);
   }
   *index = size_++;
 }
 
 
 } }  // namespace v8::internal