Added DEBUG message to ObjCARC when we transform objc_initWeak(p, null) => *p = null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171463 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/ObjCARC.cpp b/lib/Transforms/Scalar/ObjCARC.cpp
index 13d2060..3201933 100644
--- a/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/lib/Transforms/Scalar/ObjCARC.cpp
@@ -4168,6 +4168,10 @@
           ConstantPointerNull::get(cast<PointerType>(CI->getType()));
         Changed = true;
         new StoreInst(Null, CI->getArgOperand(0), CI);
+        
+        DEBUG(dbgs() << "OBJCARCContract: Old = " << *CI << "\n"
+                     << "                 New = " << *Null << "\n");
+        
         CI->replaceAllUsesWith(Null);
         CI->eraseFromParent();
       }