[Interpreter] Enable tracing of bytecode handler dispatches.

src/interpreter/interpreter-assembler.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 #define V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 
 #include "src/allocation.h"
 #include "src/base/smart-pointers.h"
 #include "src/builtins.h"
@@ skipping 149 matching lines @@
   // Returns the offset from the BytecodeArrayPointer of the current bytecode.
   compiler::Node* BytecodeOffset();
   // Returns a raw pointer to first entry in the interpreter dispatch table.
   compiler::Node* DispatchTableRawPointer();
 
   // Saves and restores interpreter bytecode offset to the interpreter stack
   // frame when performing a call.
   void CallPrologue() override;
   void CallEpilogue() override;
 
+  // Increment the dispatch counter for the (current, next) bytecode pair.
+  void TraceBytecodeDispatch(compiler::Node* target_index);
+
   // Traces the current bytecode by calling |function_id|.
   void TraceBytecode(Runtime::FunctionId function_id);
 
   // Updates the bytecode array's interrupt budget by |weight| and calls
   // Runtime::kInterrupt if counter reaches zero.
   void UpdateInterruptBudget(compiler::Node* weight);
 
   // Returns the offset of register |index| relative to RegisterFilePointer().
   compiler::Node* RegisterFrameOffset(compiler::Node* index);
 
@@ skipping 44 matching lines @@
   compiler::Node* stack_pointer_before_call_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_