Fixing retrieval of [[Class]] properties for built-in function objects, optimizing memory related to [[Class]] property.

- introduced ecma_object_get_class_name interface;
 - removed creation of [[Class]] internal property for types of objects that unambiguously determine the [[Class]] value.

Related issue: #112

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com

jerry-core/ecma/operations/ecma-objects-arguments.cpp

@@ -200,6 +200,13 @@ ecma_op_create_arguments_object (ecma_object_t *func_obj_p, /**< callee function
       // 12.
       ecma_set_object_type (obj_p, ECMA_OBJECT_TYPE_ARGUMENTS);
 
+      /*
+       * [[Class]] property is not stored explicitly for objects of ECMA_OBJECT_TYPE_ARGUMENTS type.
+       *
+       * See also: ecma_object_get_class_name
+       */
+      ecma_delete_property (obj_p, class_prop_p);
+
       ecma_property_t *parameters_map_prop_p = ecma_create_internal_property (obj_p,
                                                                               ECMA_INTERNAL_PROPERTY_PARAMETERS_MAP);
       ECMA_SET_POINTER (parameters_map_prop_p->u.internal_property.value, map_p);