Allow partial scanning of large arrays in order to avoid

src/objects-visiting.h

Index: src/objects-visiting.h
===================================================================
--- src/objects-visiting.h	(revision 12609)
+++ src/objects-visiting.h	(working copy)
@@ -213,7 +213,7 @@
                                                      start_offset);
     Object** end_slot = reinterpret_cast<Object**>(object->address() +
                                                    end_offset);
-    StaticVisitor::VisitPointers(heap, start_slot, end_slot);
+    StaticVisitor::VisitPointers(heap, start_slot, start_slot, end_slot);
   }
 };
 
@@ -283,21 +283,26 @@
     return table_.GetVisitor(map)(map, obj);
   }
 
-  static inline void VisitPointers(Heap* heap, Object** start, Object** end) {
+  static inline void VisitPointers(
+      Heap* heap, Object** anchor, Object** start, Object** end) {
     for (Object** p = start; p < end; p++) StaticVisitor::VisitPointer(heap, p);
   }
 
  private:
   static inline int VisitJSFunction(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
+    Object** start_slot =
+        HeapObject::RawField(object, JSFunction::kPropertiesOffset);
     VisitPointers(heap,
-                  HeapObject::RawField(object, JSFunction::kPropertiesOffset),
+                  start_slot,
+                  start_slot,
                   HeapObject::RawField(object, JSFunction::kCodeEntryOffset));
 
     // Don't visit code entry. We are using this visitor only during scavenges.
 
     VisitPointers(
         heap,
+        start_slot,
         HeapObject::RawField(object,
                              JSFunction::kCodeEntryOffset + kPointerSize),
         HeapObject::RawField(object,