Prototype objects never share their map, and hence cannot be in deprecated state.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index d4af4a6255c1d1d1765f8d66ea2e7c0e1436978e..8b6f1e2e621c39339c02891c090b12b83add0df8 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6068,12 +6068,9 @@ class Map: public HeapObject {
   // Returns a non-deprecated version of the input. If the input was not
   // deprecated, it is directly returned. Otherwise, the non-deprecated version
   // is found by re-transitioning from the root of the transition tree using the
-  // descriptor array of the map. Returns NULL if no updated map is found.
-  // This method also applies any pending migrations along the prototype chain.
+  // descriptor array of the map. Returns MaybeHandle<Map>() if no updated map
+  // is found.
   static MaybeHandle<Map> TryUpdate(Handle<Map> map) WARN_UNUSED_RESULT;
-  // Same as above, but does not touch the prototype chain.
-  static MaybeHandle<Map> TryUpdateInternal(Handle<Map> map)
-      WARN_UNUSED_RESULT;
 
   // Returns a non-deprecated version of the input. This method may deprecate
   // existing maps along the way if encodings conflict. Not for use while