QA -mb_convert_encoding_array - error for object item in array

Closes GH-9023.

Author: jcm

ext/mbstring/tests/mb_convert_encoding_array_error_001.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Test mb_convert_encoding() function : array functionality with objects not supported
+--EXTENSIONS--
+mbstring
+--FILE--
+<?php
+mb_convert_encoding(["key" => new stdClass()], 'UTF-8');
+?>
+--EXPECTF--
+Warning: mb_convert_encoding(): Object is not supported in %s on line %d