[Interpreter] Bytecodes for exchanging registers.

src/interpreter/bytecode-array-iterator.cc

Index: src/interpreter/bytecode-array-iterator.cc
diff --git a/src/interpreter/bytecode-array-iterator.cc b/src/interpreter/bytecode-array-iterator.cc
index 0bdd0553152975c9d73e337c885ba2c3f1815ad2..9af4c5a29ab2c7f7a40859ce3e4e510dbc63a9a4 100644
--- a/src/interpreter/bytecode-array-iterator.cc
+++ b/src/interpreter/bytecode-array-iterator.cc
@@ -75,11 +75,11 @@ int BytecodeArrayIterator::GetCountOperand(int operand_index) const {
 
 
 int BytecodeArrayIterator::GetIndexOperand(int operand_index) const {
-  OperandSize size =
-      Bytecodes::GetOperandSize(current_bytecode(), operand_index);
-  OperandType type =
-      (size == OperandSize::kByte) ? OperandType::kIdx8 : OperandType::kIdx16;
-  uint32_t operand = GetRawOperand(operand_index, type);
+  OperandType operand_type =
+      Bytecodes::GetOperandType(current_bytecode(), operand_index);
+  DCHECK(operand_type == OperandType::kIdx8 ||
+         operand_type == OperandType::kIdx16);
+  uint32_t operand = GetRawOperand(operand_index, operand_type);
   return static_cast<int>(operand);
 }
 
@@ -88,7 +88,8 @@ Register BytecodeArrayIterator::GetRegisterOperand(int operand_index) const {
   OperandType operand_type =
       Bytecodes::GetOperandType(current_bytecode(), operand_index);
   DCHECK(operand_type == OperandType::kReg8 ||
-         operand_type == OperandType::kMaybeReg8);
+         operand_type == OperandType::kMaybeReg8 ||
+         operand_type == OperandType::kReg16);
   uint32_t operand = GetRawOperand(operand_index, operand_type);
   return Register::FromOperand(operand);
 }