[Intepreter] Extend and move Register class.

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index 8a45c73bbbcbb4a7bd44ca05142c8ad63da08b4d..cc34eb3cdffa228980849b188b4218108ad7aa3f 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -8,7 +8,6 @@
 #include <vector>
 
 #include "src/ast.h"
-#include "src/frames.h"
 #include "src/identity-map.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/zone.h"
@@ -58,9 +57,6 @@ class BytecodeArrayBuilder {
   BytecodeArrayBuilder& Return();
 
  private:
-  static const int kLastParamRegisterIndex =
-      -InterpreterFrameConstants::kLastParamFromRegisterPointer / kPointerSize;
-
   static Bytecode BytecodeForBinaryOperation(Token::Value op);
 
   void Output(Bytecode bytecode, uint8_t r0, uint8_t r1, uint8_t r2);
@@ -106,9 +102,9 @@ class Register {
 
   int index() { return index_; }
 
-  uint8_t ToOperand() { return static_cast<uint8_t>(-index_); }
+  uint8_t ToOperand() { return Bytecodes::RegisterIndexToOperand(index_); }
   static Register FromOperand(uint8_t operand) {
-    return Register(-static_cast<int8_t>(operand));
+    return Register(Bytecodes::RegisterIndexFromOperand(operand));
   }
 
  private: