Fix VC++ level 4 warnings. Because a base class has declared these private, VC++ complains it cannot automatically generate this methods.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24751 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Instruction.h

@@ -27,6 +27,9 @@ template<typename ValueSubClass, typename ItemParentClass, typename SymTabClass,
          typename SubClass> class SymbolTableListTraits;
 
 class Instruction : public User {
+  void operator=(const Instruction &);     // Do not implement
+  Instruction(const Instruction &);        // Do not implement
+
   BasicBlock *Parent;
   Instruction *Prev, *Next; // Next and Prev links for our intrusive linked list