[Interpreter] Add option to trace bytecode execution.

src/interpreter/bytecodes.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_BYTECODES_H_
 #define V8_INTERPRETER_BYTECODES_H_
 
 #include <iosfwd>
 
 // Clients of this interface shouldn't depend on lots of interpreter internals.
@@ skipping 326 matching lines @@
   uint16_t ToWideOperand() const;
 
   static Register FromRawOperand(uint32_t raw_operand);
   uint32_t ToRawOperand() const;
 
   static bool AreContiguous(Register reg1, Register reg2,
                             Register reg3 = Register(),
                             Register reg4 = Register(),
                             Register reg5 = Register());
 
+  std::string ToString(int parameter_count);
+
   bool operator==(const Register& other) const {
     return index() == other.index();
   }
   bool operator!=(const Register& other) const {
     return index() != other.index();
   }
   bool operator<(const Register& other) const {
     return index() < other.index();
   }
   bool operator<=(const Register& other) const {
@@ skipping 113 matching lines @@
 
 std::ostream& operator<<(std::ostream& os, const Bytecode& bytecode);
 std::ostream& operator<<(std::ostream& os, const OperandType& operand_type);
 std::ostream& operator<<(std::ostream& os, const OperandSize& operand_type);
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODES_H_