Rework error to use a global slot to store the error value.

This change frees up the error bit in ecma_value_t, which allows
to define 4 more value types (e.g. symbols). To keep API
compatibility we introduce a box for values with error flag.

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

jerry-core/ecma/operations/ecma-function-object.c

@@ -468,6 +468,12 @@ ecma_op_function_call (ecma_object_t *func_obj_p, /**< Function object */
                                                        this_arg_value,
                                                        arguments_list_p,
                                                        arguments_list_len);
+
+    if (unlikely (ecma_is_value_error_reference (ret_value)))
+    {
+      JERRY_CONTEXT (error_value) = ecma_clear_error_reference (ret_value);
+      ret_value = ecma_make_simple_value (ECMA_SIMPLE_VALUE_ERROR);
+    }
   }
   else
   {