Added functions malloc_referenced[_{acquire,release}]() that implement

reference counted memory allocations. Can be used for sharing immutable
structures.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24666 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/heap.h

@@ -26,6 +26,10 @@ void *memalign(size_t alignment, size_t size);
 
 void deferred_free(void* block);
 
+void* malloc_referenced(size_t size);
+void* malloc_referenced_acquire(void* data);
+void malloc_referenced_release(void* data);
+
 status_t heap_init(addr_t heapBase, size_t heapSize);
 status_t heap_init_post_sem();
 status_t heap_init_post_thread();