[interpreter] Add support for scalable operands.

src/interpreter/bytecode-array-iterator.h

Index: src/interpreter/bytecode-array-iterator.h
diff --git a/src/interpreter/bytecode-array-iterator.h b/src/interpreter/bytecode-array-iterator.h
index 5379bbf0288d3140db0e8114b2f7080c924289f1..6c10938e8892dbca7035d1ce53af01c6d7b22030 100644
--- a/src/interpreter/bytecode-array-iterator.h
+++ b/src/interpreter/bytecode-array-iterator.h
@@ -23,20 +23,26 @@ class BytecodeArrayIterator {
   int current_bytecode_size() const;
   void set_current_offset(int offset) { bytecode_offset_ = offset; }
   int current_offset() const { return bytecode_offset_; }
+  int current_operand_scale() const { return operand_scale_; }
+  int current_prefix_offset() const { return prefix_offset_; }
   const Handle<BytecodeArray>& bytecode_array() const {
     return bytecode_array_;
   }
 
-  int8_t GetImmediateOperand(int operand_index) const;
-  int GetIndexOperand(int operand_index) const;
-  int GetRegisterCountOperand(int operand_index) const;
+  uint32_t GetFlagOperand(int operand_index) const;
+  int32_t GetImmediateOperand(int operand_index) const;
+  uint32_t GetIndexOperand(int operand_index) const;
+  uint32_t GetRegisterCountOperand(int operand_index) const;
   Register GetRegisterOperand(int operand_index) const;
   int GetRegisterOperandRange(int operand_index) const;
+  uint32_t GetRuntimeIdOperand(int operand_index) const;
   Handle<Object> GetConstantForIndexOperand(int operand_index) const;
 
   // Get the raw byte for the given operand. Note: you should prefer using the
   // typed versions above which cast the return to an appropriate type.
   uint32_t GetRawOperand(int operand_index, OperandType operand_type) const;
+  int32_t GetRawOperandSigned(int operand_index,
+                              OperandType operand_type) const;
 
   // Returns the absolute offset of the branch target at the current
   // bytecode. It is an error to call this method if the bytecode is
@@ -44,8 +50,12 @@ class BytecodeArrayIterator {
   int GetJumpTargetOffset() const;
 
  private:
+  void update_operand_scale();
+
   Handle<BytecodeArray> bytecode_array_;
   int bytecode_offset_;
+  int operand_scale_;
+  int prefix_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodeArrayIterator);
 };