Added DEBUG message for ObjCARC when an inline asm marker is inserted for architectures where this is required to perform a retainAutoreleasedReturnValue optimization.

llvm-svn: 171462
diff --git a/llvm/lib/Transforms/Scalar/ObjCARC.cpp b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
index ab2dc40..13d2060 100644
--- a/llvm/lib/Transforms/Scalar/ObjCARC.cpp
+++ b/llvm/lib/Transforms/Scalar/ObjCARC.cpp
@@ -4147,6 +4147,8 @@
       } while (isNoopInstruction(BBI));
 
       if (&*BBI == GetObjCArg(Inst)) {
+        DEBUG(dbgs() << "ObjCARCContract: Adding inline asm marker for "
+              "retainAutoreleasedReturnValue optimization.\n");
         Changed = true;
         InlineAsm *IA =
           InlineAsm::get(FunctionType::get(Type::getVoidTy(Inst->getContext()),