[Interpreter] Add support for local context loads and stores.

src/interpreter/bytecodes.h

Index: src/interpreter/bytecodes.h
diff --git a/src/interpreter/bytecodes.h b/src/interpreter/bytecodes.h
index f98882a5dd427950d38feae4d85ed431eba70542..50c338dc9583693c892b194c901191184ad5d42f 100644
--- a/src/interpreter/bytecodes.h
+++ b/src/interpreter/bytecodes.h
@@ -48,7 +48,10 @@ namespace interpreter {
   V(StaGlobal, OperandType::kIdx8)                                             \
                                                                                \
   /* 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)                                                  \
@@ -68,10 +71,6 @@ namespace interpreter {
   V(KeyedStoreICStrict, OperandType::kReg8, OperandType::kReg8,                \
     OperandType::kIdx8)                                                        \
                                                                                \
-  /* Context operations */                                                     \
-  V(PushContext, OperandType::kReg8)                                           \
-  V(PopContext, OperandType::kReg8)                                            \
-                                                                               \
   /* Binary Operators */                                                       \
   V(Add, OperandType::kReg8)                                                   \
   V(Sub, OperandType::kReg8)                                                   \
@@ -206,6 +205,9 @@ class Register {
                             Register reg4 = Register(),
                             Register reg5 = Register());
 
+  bool operator==(const Register& o) const { return o.index() == index(); }
+  bool operator!=(const Register& o) const { return o.index() != index(); }
+
  private:
   static const int kIllegalIndex = kMaxInt;