Use LLVM_DELETED_FUNCTION in place of 'DO NOT IMPLEMENT' comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163974 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index f242df4..0ff4664 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -197,7 +197,7 @@
   /// @brief A class for maintaining the slot number definition
   /// as a placeholder for the actual definition for forward constants defs.
   class ConstantPlaceHolder : public ConstantExpr {
-    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
+    void operator=(const ConstantPlaceHolder &) LLVM_DELETED_FUNCTION;
   public:
     // allocate space for exactly one operand
     void *operator new(size_t s) {