Fix lazy deopt after tagged binary ops

src/heap.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 596 matching lines @@
 
   AllowHeapAllocation for_the_rest_of_the_epilogue;
 
 #ifdef DEBUG
   if (FLAG_print_global_handles) isolate_->global_handles()->Print();
   if (FLAG_print_handles) PrintHandles();
   if (FLAG_gc_verbose) Print();
   if (FLAG_code_stats) ReportCodeStatistics("After GC");
 #endif
   if (FLAG_deopt_every_n_garbage_collections > 0) {
+    // TODO(jkummerow/ulan/jarin): This is not safe! We can't assume that
+    // the topmost optimized frame can be deoptimized safely, because it
+    // might not have a lazy bailout point right after its current PC.
     if (++gcs_since_last_deopt_ == FLAG_deopt_every_n_garbage_collections) {
       Deoptimizer::DeoptimizeAll(isolate());
       gcs_since_last_deopt_ = 0;
     }
   }
 
   UpdateMaximumCommitted();
 
   isolate_->counters()->alive_after_last_gc()->Set(
       static_cast<int>(SizeOfObjects()));
@@ skipping 7085 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   OS::MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   OS::MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal