Pretenure call new support.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 6493524fcb51633e94294a3e83e85fa4f2b8be69..b740277f1642db61272e4474044c06d60742a2c5 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -4403,15 +4403,17 @@ MaybeObject* Heap::AllocateJSObjectWithAllocationSite(JSFunction* constructor,
   // Allocate the object based on the constructors initial map, or the payload
   // advice
   Map* initial_map = constructor->initial_map();
-
-  ElementsKind to_kind = allocation_site->GetElementsKind();
   AllocationSiteMode mode = TRACK_ALLOCATION_SITE;
-  if (to_kind != initial_map->elements_kind()) {
-    MaybeObject* maybe_new_map = initial_map->AsElementsKind(to_kind);
-    if (!maybe_new_map->To(&initial_map)) return maybe_new_map;
-    // Possibly alter the mode, since we found an updated elements kind
-    // in the type info cell.
-    mode = AllocationSite::GetMode(to_kind);
+
+  if (initial_map->instance_type() == JS_ARRAY_TYPE) {
+    ElementsKind to_kind = allocation_site->GetElementsKind();
+    if (to_kind != initial_map->elements_kind()) {
+      MaybeObject* maybe_new_map = initial_map->AsElementsKind(to_kind);
+      if (!maybe_new_map->To(&initial_map)) return maybe_new_map;
+      // Possibly alter the mode, since we found an updated elements kind
+      // in the type info cell.
+      mode = AllocationSite::GetMode(to_kind);
+    }
   }
 
   MaybeObject* result;