ARM: Implement runtime function for array literal transitions.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 2a07ca360b1f61d9f33f3b19c89691c711144208..4ab103ea590126bc7661dc695fd4c48709effeb0 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9497,6 +9497,9 @@ MUST_USE_RESULT MaybeObject* JSObject::TransitionElementsKind(
       MaybeObject* maybe_new_map = GetElementsTransitionMap(FAST_ELEMENTS);
       Map* new_map;
       if (!maybe_new_map->To(&new_map)) return maybe_new_map;
+      if (FLAG_trace_elements_transitions) {
+        PrintElementsTransition(stdout, from_kind, elms, FAST_ELEMENTS, elms);
+      }
       set_map(new_map);
       return this;
     }