[Interpreter] Enable assignments in expressions.

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 51 matching lines @@
   /* Context operations */                                                     \
   V(PushContext, OperandType::kReg8)                                           \
   V(PopContext, OperandType::kReg8)                                            \
   V(LdaContextSlot, OperandType::kReg8, OperandType::kIdx8)                    \
   V(StaContextSlot, OperandType::kReg8, OperandType::kIdx8)                    \
                                                                                \
   /* Register-accumulator transfers */                                         \
   V(Ldar, OperandType::kReg8)                                                  \
   V(Star, OperandType::kReg8)                                                  \
                                                                                \
+  /* Register-register transfers */                                            \
+  V(Mov, OperandType::kReg8, OperandType::kReg8)                               \
+                                                                               \
   /* LoadIC operations */                                                      \
   V(LoadICSloppy, OperandType::kReg8, OperandType::kIdx8, OperandType::kIdx8)  \
   V(LoadICStrict, OperandType::kReg8, OperandType::kIdx8, OperandType::kIdx8)  \
   V(KeyedLoadICSloppy, OperandType::kReg8, OperandType::kIdx8)                 \
   V(KeyedLoadICStrict, OperandType::kReg8, OperandType::kIdx8)                 \
   /* TODO(rmcilroy): Wide register operands too? */                            \
   V(LoadICSloppyWide, OperandType::kReg8, OperandType::kIdx16,                 \
     OperandType::kIdx16)                                                       \
   V(LoadICStrictWide, OperandType::kReg8, OperandType::kIdx16,                 \
     OperandType::kIdx16)                                                       \
@@ skipping 262 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_