/usr/lib/mysql-testsuite/t/mysqld--help-win.test is in percona-xtradb-cluster-testsuite-5.5 5.5.34-25.9+dfsg-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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# mysqld --help
#
--source include/not_embedded.inc
--source include/windows.inc
--source include/have_perfschema.inc
--source include/mysqld--help.inc
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