[Intepreter] Extend and move Register class.

src/interpreter/bytecodes.h

Index: src/interpreter/bytecodes.h
diff --git a/src/interpreter/bytecodes.h b/src/interpreter/bytecodes.h
index a5b34f791afcfa1ca7101a4333e9dcd34a3b8403..9d7137b285392efc9c62a917b676bb6109d5b194 100644
--- a/src/interpreter/bytecodes.h
+++ b/src/interpreter/bytecodes.h
@@ -105,8 +105,25 @@ class Bytecodes {
   // Maximum size of a bytecode and its operands.
   static int MaximumSize();
 
+  // Returns the operand value for register with the specified index.
+  static uint8_t RegisterIndexToOperand(int index);
+
+  // Returns the register index for a register operand.
+  static int RegisterIndexFromOperand(uint8_t operand);
+
+  // Returns the operand value for parameter with the specified index.
+  static uint8_t ParameterIndexToOperand(int index, int number_of_parameters);
+
+  // Returns the maximum number of parameters including this.
+  static int MaximumNumberOfParameters();
+
+  // Returns the parameter index for a parameter operand.
+  static int ParameterIndexFromOperand(uint8_t operand,
+                                       int number_of_parameters);
+
   // Decode a single bytecode and operands to |os|.
-  static std::ostream& Decode(std::ostream& os, const uint8_t* bytecode_start);
+  static std::ostream& Decode(std::ostream& os, const uint8_t* bytecode_start,
+                              int number_of_parameters);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(Bytecodes);