Keep track in chained PCH of implicit members that were added after the definition was completed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTCommon.h b/lib/Serialization/ASTCommon.h
index 36958c7..5ed607a 100644
--- a/lib/Serialization/ASTCommon.h
+++ b/lib/Serialization/ASTCommon.h
@@ -21,7 +21,8 @@
 namespace serialization {
 
 enum DeclUpdateKind {
-  UPD_CXX_SET_DEFINITIONDATA
+  UPD_CXX_SET_DEFINITIONDATA,
+  UPD_CXX_ADDED_IMPLICIT_MEMBER
 };
 
 TypeIdx TypeIdxFromBuiltin(const BuiltinType *BT);