Add macros for accessor functions to ConstantPlaceHolder

[rtrieu]

Summary

Judging from other derived classes of ConstantExpr, there should accessor functions in ConstantPlaceHolder. This patch adds the macros that will declare and define these functions. This also fixes the constructor so that it will not trigger a future -Wuninitialized warning.

[rtrieu]

Ping.

[rtrieu]

Ping.

lib/Bitcode/Reader/BitcodeReader.cpp

public:
     /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
     static bool classof(const Value *V) {
       return isa<ConstantExpr>(V) &&
              cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
     }
 
 
     /// Provide fast operand accessors
-    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
+    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
   };
 }
 
 // FIXME: can we inherit this from ConstantExpr?
 template <>
 struct OperandTraits<ConstantPlaceHolder> :
   public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
 };
+DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
 }
 
 
 void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
   if (Idx == size()) {
     push_back(V);
     return;
   }