libvlc: add leak debugging code

disabled by default

src/libvlc.c

@@ -450,6 +450,16 @@ void libvlc_InternalDestroy( libvlc_int_t *p_libvlc )
 
     vlc_ExitDestroy( &priv->exit );
 
+#if 0
+    {
+        vlc_object_internals_t *internal = vlc_internals(p_libvlc);
+        if (atomic_load(&internal->refs) != 1)
+        {
+            fprintf(stderr, "=== vlc_object LEAKS detected ===\n");
+            DumpStructureLocked(VLC_OBJECT(p_libvlc), stderr, 0);
+        }
+    }
+#endif
     assert( atomic_load(&(vlc_internals(p_libvlc)->refs)) == 1 );
     vlc_object_delete(p_libvlc);
 }