[d8] Fix the shared-library build

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 5e476f66a64d5c0348be4089e3b31b655ea008a5..41e0727a3fbe9a634dff2bde325fd996b9951de9 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -463,7 +463,7 @@ class MemoryChunk {
   }
   inline LocalArrayBufferTracker* local_tracker() { return local_tracker_; }
 
-  void AllocateOldToNewSlots();
+  V8_EXPORT_PRIVATE void AllocateOldToNewSlots();
   void ReleaseOldToNewSlots();
   void AllocateOldToOldSlots();
   void ReleaseOldToOldSlots();
@@ -1430,7 +1430,7 @@ class MemoryAllocator {
 //       method which is used to avoid using virtual functions
 //       iterating a specific space.
 
-class ObjectIterator : public Malloced {
+class V8_EXPORT_PRIVATE ObjectIterator : public Malloced {
  public:
   virtual ~ObjectIterator() {}
   virtual HeapObject* Next() = 0;
@@ -1481,7 +1481,7 @@ class PageRange {
 // If objects are allocated in the page during iteration the iterator may
 // or may not iterate over those objects.  The caller must create a new
 // iterator in order to be sure to visit these new objects.
-class HeapObjectIterator : public ObjectIterator {
+class V8_EXPORT_PRIVATE HeapObjectIterator : public ObjectIterator {
  public:
   // Creates a new object iterator in a given space.
   explicit HeapObjectIterator(PagedSpace* space);