Fix the regressions my User changes introduced.  Apparently some parts of
LLVM make the very reasonable assumption that constant expressions will
have at least one operand! :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19943 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bytecode/Reader/Reader.cpp b/lib/Bytecode/Reader/Reader.cpp
index a36aa99..cf68d67 100644
--- a/lib/Bytecode/Reader/Reader.cpp
+++ b/lib/Bytecode/Reader/Reader.cpp
@@ -38,8 +38,11 @@
     ConstantPlaceHolder();                       // DO NOT IMPLEMENT
     void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
   public:
+    Use Op;
     ConstantPlaceHolder(const Type *Ty) 
-      : ConstantExpr(Ty, Instruction::UserOp1, 0, 0) {}
+      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
+        Op(UndefValue::get(Type::IntTy), this) {
+    }
   };
 }