Use the ASTMutationListener to track added template specializations in a chained PCH.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117533 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTCommon.h b/lib/Serialization/ASTCommon.h
index 5ed607a..5ded805 100644
--- a/lib/Serialization/ASTCommon.h
+++ b/lib/Serialization/ASTCommon.h
@@ -22,7 +22,8 @@
 
 enum DeclUpdateKind {
   UPD_CXX_SET_DEFINITIONDATA,
-  UPD_CXX_ADDED_IMPLICIT_MEMBER
+  UPD_CXX_ADDED_IMPLICIT_MEMBER,
+  UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION
 };
 
 TypeIdx TypeIdxFromBuiltin(const BuiltinType *BT);