Deprecate obsolete JSFunction::unchecked_shared accessor.

src/mark-compact.cc

Index: src/mark-compact.cc
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index dc2db4b096b76ddb7c36532a51be7106c9b6838b..3fdb2a0c6372661fc36759542a4ceb2553506e72 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -2418,7 +2418,7 @@ void MarkCompactCollector::ClearNonLiveReferences() {
       // This map is used for inobject slack tracking and has been detached
       // from SharedFunctionInfo during the mark phase.
       // Since it survived the GC, reattach it now.
-      map->unchecked_constructor()->unchecked_shared()->AttachInitialMap(map);
+      map->unchecked_constructor()->shared()->AttachInitialMap(map);
     }
 
     ClearNonLivePrototypeTransitions(map);