Introduce the core infrastructure needed to model a complete
redeclaration chain for Objective-C classes, including:
  - Using the first declaration as the canonical declaration.
  - Using the definition as the primary DeclContext
  - Making sure that all declarations have a pointer to the definition
  data, and the definition knows that it is the definition.
  - Serialization support for when a definition gets added to a
  declaration that comes from an AST file.

However, note that we're not taking advantage of much of this code
yet, because we're still re-using ObjCInterfaceDecls.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146667 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Serialization/ASTCommon.h b/lib/Serialization/ASTCommon.h
index 367f57f..2e3d70b 100644
--- a/lib/Serialization/ASTCommon.h
+++ b/lib/Serialization/ASTCommon.h
@@ -26,7 +26,8 @@
   UPD_CXX_ADDED_IMPLICIT_MEMBER,
   UPD_CXX_ADDED_TEMPLATE_SPECIALIZATION,
   UPD_CXX_ADDED_ANONYMOUS_NAMESPACE,
-  UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER
+  UPD_CXX_INSTANTIATED_STATIC_DATA_MEMBER,
+  UPD_OBJC_SET_CLASS_DEFINITIONDATA
 };
 
 TypeIdx TypeIdxFromBuiltin(const BuiltinType *BT);