[Interpreter] Add dispatch counters for each bytecode.

src/interpreter/interpreter.h

Index: src/interpreter/interpreter.h
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index 647f95849d004dbc9e17dde14707e5f4b8f35a0e..c9a0004ae738eb020684483eb6c6396336b719c8 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -53,6 +53,10 @@ class Interpreter {
     return reinterpret_cast<Address>(&dispatch_table_[0]);
   }
 
+  uint32_t* handlers_dispatch_counters() {
+    return &handlers_dispatch_counters_[0];
+  }
+
  private:
 // Bytecode handler generator functions.
 #define DECLARE_BYTECODE_HANDLER_GENERATOR(Name, ...) \
@@ -136,6 +140,7 @@ class Interpreter {
 
   Isolate* isolate_;
   Code* dispatch_table_[kDispatchTableSize];
+  uint32_t handlers_dispatch_counters_[kDispatchTableSize];
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };