Add reference support for native pointers. (#4615)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/include/jerryscript-core.h

@@ -247,6 +247,11 @@ void jerry_set_object_native_pointer (const jerry_value_t obj_val,
                                       const jerry_object_native_info_t *native_info_p);
 bool jerry_delete_object_native_pointer (const jerry_value_t obj_val,
                                          const jerry_object_native_info_t *native_info_p);
+void jerry_native_pointer_init_references (void *native_pointer_p,
+                                           const jerry_object_native_info_t *native_info_p);
+void jerry_native_pointer_release_references (void *native_pointer_p,
+                                              const jerry_object_native_info_t *native_info_p);
+void jerry_native_pointer_set_reference (jerry_value_t *reference_p, jerry_value_t value);
 
 bool jerry_objects_foreach (jerry_objects_foreach_t foreach_p,
                             void *user_data);

jerry-core/include/jerryscript-types.h

@@ -387,6 +387,9 @@ typedef void *(*jerry_context_alloc_t) (size_t size, void *cb_data_p);
 typedef struct jerry_object_native_info_t
 {
   jerry_object_native_free_callback_t free_cb; /**< the free callback of the native pointer */
+  uint16_t number_of_references; /**< the number of value references which are marked by the garbage collector */
+  uint16_t offset_of_references; /**< byte offset indicating the start offset of value
+                                  *   references in the user allocated buffer */
 } jerry_object_native_info_t;
 
 /**