[Interpreter] Add support for loading literals from the constant pool.

src/interpreter/bytecodes.h

Index: src/interpreter/bytecodes.h
diff --git a/src/interpreter/bytecodes.h b/src/interpreter/bytecodes.h
index c4457499768b8440a1b47531b4f2e24409dfadd6..a5b34f791afcfa1ca7101a4333e9dcd34a3b8403 100644
--- a/src/interpreter/bytecodes.h
+++ b/src/interpreter/bytecodes.h
@@ -19,6 +19,7 @@ namespace interpreter {
 #define OPERAND_TYPE_LIST(V) \
   V(None)                    \
   V(Imm8)                    \
+  V(Idx)                     \
   V(Reg)
 
 // The list of bytecodes which are interpreted by the interpreter.
@@ -27,6 +28,7 @@ namespace interpreter {
   /* Loading the accumulator */        \
   V(LdaZero, OperandType::kNone)       \
   V(LdaSmi8, OperandType::kImm8)       \
+  V(LdaConstant, OperandType::kIdx)    \
   V(LdaUndefined, OperandType::kNone)  \
   V(LdaNull, OperandType::kNone)       \
   V(LdaTheHole, OperandType::kNone)    \