Multi-page growing and shrinking new-space

src/objects-visiting.h

Index: src/objects-visiting.h
diff --git a/src/objects-visiting.h b/src/objects-visiting.h
index 904cb16c99fdec652d7e991e5e9cda44894ee107..b87ba706424324ccc549cd171952fed6136cbd5e 100644
--- a/src/objects-visiting.h
+++ b/src/objects-visiting.h
@@ -295,6 +295,10 @@ class StaticNewSpaceVisitor : public StaticVisitorBase {
         SeqTwoByteStringSize(map->instance_type());
   }
 
+  static inline int VisitFreeSpace(Map* map, HeapObject* object) {
+    return FreeSpace::cast(object)->Size();
+  }
+
   class DataObjectVisitor {
    public:
     template<int object_size>