[Interpreter] Adds support for const/let variables to interpreter.

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 217 matching lines @@
   V(JumpIfToBooleanTrueConstantWide, OperandType::kIdx16)                      \
   V(JumpIfToBooleanFalse, OperandType::kImm8)                                  \
   V(JumpIfToBooleanFalseConstant, OperandType::kIdx8)                          \
   V(JumpIfToBooleanFalseConstantWide, OperandType::kIdx16)                     \
   V(JumpIfNull, OperandType::kImm8)                                            \
   V(JumpIfNullConstant, OperandType::kIdx8)                                    \
   V(JumpIfNullConstantWide, OperandType::kIdx16)                               \
   V(JumpIfUndefined, OperandType::kImm8)                                       \
   V(JumpIfUndefinedConstant, OperandType::kIdx8)                               \
   V(JumpIfUndefinedConstantWide, OperandType::kIdx16)                          \
+  V(JumpIfHole, OperandType::kImm8)                                            \
+  V(JumpIfNotHole, OperandType::kImm8)                                         \

[rmcilroy, 2016/01/26 14:37:28]

It seems dangerous to have these without Constant and ConstantWide variants of
this Bytecode as well. I'm assuming these aren't needed now due to the way these
jumps are used, and it's probably not worth adding them if we are going to add
explicit assignment+throw bytecodes. If so, please add a TODO that these should
be removed once we have these bytecodes, or that we should add wide variants).

[mythria, 2016/02/01 10:02:18]

Done.

                                                                                \
   /* Complex flow control For..in */                                           \
   V(ForInPrepare, OperandType::kRegTriple8)                                    \
   V(ForInPrepareWide, OperandType::kRegTriple16)                               \
   V(ForInDone, OperandType::kReg8, OperandType::kReg8)                         \
   V(ForInNext, OperandType::kReg8, OperandType::kReg8, OperandType::kRegPair8) \
   V(ForInNextWide, OperandType::kReg16, OperandType::kReg16,                   \
     OperandType::kRegPair16)                                                   \
   V(ForInStep, OperandType::kReg8)                                             \
                                                                                \
   /* Non-local flow control */                                                 \
   V(Throw, OperandType::kNone)                                                 \
   V(ReThrow, OperandType::kNone)                                               \
   V(Return, OperandType::kNone)
 
-
 // Enumeration of the size classes of operand types used by bytecodes.
 enum class OperandSize : uint8_t {
   kNone = 0,
   kByte = 1,
   kShort = 2,
 };
 
 
 // Enumeration of operand types used by bytecodes.
 enum class OperandType : uint8_t {
@@ skipping 176 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_