Handle dereferencing needs to be allowed for printing during optimization phase.

src/hydrogen.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 10770 matching lines @@
   if (FLAG_hydrogen_stats) {
     int64_t end = OS::Ticks();
     unsigned size = Zone::allocation_size_ - start_allocation_size_;
     HStatistics::Instance()->SaveTiming(name_, end - start_, size);
   }
 
   // Produce trace output if flag is set so that the first letter of the
   // phase name matches the command line parameter FLAG_trace_phase.
   if (FLAG_trace_hydrogen &&
       OS::StrChr(const_cast<char*>(FLAG_trace_phase), name_[0]) != NULL) {
+    AllowHandleDereference allow_handle_deref(graph_->isolate());
     if (graph_ != NULL) HTracer::Instance()->TraceHydrogen(name_, graph_);
     if (chunk_ != NULL) HTracer::Instance()->TraceLithium(name_, chunk_);
     if (allocator_ != NULL) {
       HTracer::Instance()->TraceLiveRanges(name_, allocator_);
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal