Implement attribute 'ns_autorelease'.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@70990 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 98ed063..9b14a94 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1552,6 +1552,7 @@
     case Attr::CFOwnershipRelease:
     case Attr::CFOwnershipRetain:
     case Attr::CFOwnershipReturns:
+    case Attr::NSOwnershipAutorelease:
     case Attr::NSOwnershipRelease:
     case Attr::NSOwnershipRetain:
     case Attr::NSOwnershipReturns: