Avoid handle dereference during graph optimization.

src/isolate.h

 // 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 951 matching lines @@
   inline bool DebuggerHasBreakPoints();
 
 #ifdef DEBUG
   HistogramInfo* heap_histograms() { return heap_histograms_; }
 
   JSObject::SpillInformation* js_spill_information() {
     return &js_spill_information_;
   }
 
   int* code_kind_statistics() { return code_kind_statistics_; }
+
+  bool allow_handle_deref() { return allow_handle_deref_; }
+  void set_allow_handle_deref(bool allow) { allow_handle_deref_ = allow; }
 #endif
 
 #if defined(V8_TARGET_ARCH_ARM) && !defined(__arm__) || \
     defined(V8_TARGET_ARCH_MIPS) && !defined(__mips__)
   bool simulator_initialized() { return simulator_initialized_; }
   void set_simulator_initialized(bool initialized) {
     simulator_initialized_ = initialized;
   }
 
   HashMap* simulator_i_cache() { return simulator_i_cache_; }
@@ skipping 277 matching lines @@
   bool simulator_initialized_;
   HashMap* simulator_i_cache_;
   Redirection* simulator_redirection_;
 #endif
 
 #ifdef DEBUG
   // A static array of histogram info for each type.
   HistogramInfo heap_histograms_[LAST_TYPE + 1];
   JSObject::SpillInformation js_spill_information_;
   int code_kind_statistics_[Code::NUMBER_OF_KINDS];
+
+  bool allow_handle_deref_;
 #endif
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
   Debugger* debugger_;
   Debug* debug_;
 #endif
 
 #define GLOBAL_BACKING_STORE(type, name, initialvalue)                         \
   type name##_;
   ISOLATE_INIT_LIST(GLOBAL_BACKING_STORE)
@@ skipping 165 matching lines @@
 
 // Mark the native context with out of memory.
 inline void Context::mark_out_of_memory() {
   native_context()->set_out_of_memory(HEAP->true_value());
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_