Improve positions tracking inside the HGraphBuilder.

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 1090 matching lines @@
     function_entry_hook_ = function_entry_hook;
   }
 
   void* stress_deopt_count_address() { return &stress_deopt_count_; }
 
   inline RandomNumberGenerator* random_number_generator();
 
   // Given an address occupied by a live code object, return that object.
   Object* FindCodeObject(Address a);
 
+  int NextOptimizationId() {
+    int id = next_optimization_id_++;
+    if (!Smi::IsValid(next_optimization_id_)) {
+      next_optimization_id_ = 0;
+    }
+    return id;
+  }
+
  private:
   Isolate();
 
   friend struct GlobalState;
   friend struct InitializeGlobalState;
 
   enum State {
     UNINITIALIZED,    // Some components may not have been allocated.
     INITIALIZED       // All components are fully initialized.
   };
@@ skipping 212 matching lines @@
   SweeperThread** sweeper_thread_;
   int num_sweeper_threads_;
 
   // TODO(yangguo): This will become obsolete once ResourceConstraints
   // becomes an argument to Isolate constructor.
   int max_available_threads_;
 
   // Counts deopt points if deopt_every_n_times is enabled.
   unsigned int stress_deopt_count_;
 
+  int next_optimization_id_;
+
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
   friend class IsolateInitializer;
   friend class OptimizingCompilerThread;
   friend class SweeperThread;
   friend class ThreadManager;
   friend class Simulator;
   friend class StackGuard;
   friend class ThreadId;
   friend class TestMemoryAllocatorScope;
@@ skipping 191 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_