[ticket/11465] Add comments explaining the tests

PHPBB3-11465

tests/extension/ext/foo/acp/fail_info.php

@@ -1,5 +1,8 @@
 <?php
-
+/*
+* Due to the mismatch between the class name and the file name, this module
+* file shouldn't be found by the extension finder
+*/
 class phpbb_ext_foo_acp_foo_info
 {
 	public function module()

tests/extension/ext/foo/acp/fail_module.php

@@ -1,5 +1,8 @@
 <?php
-
+/*
+* Due to the mismatch between the class name and the file name of the module
+* info file, this module's info file shouldn't be found
+*/
 class phpbb_ext_foo_acp_fail_module
 {
 }