The ``_os_random_weak`` function is the only non-static function
besides ``_ZSt15get_new_handlerv`` that is not prefixed with ``mi`` or
``_mi``.
The discrepancy was discovered by CPython's smelly script. The checker
looks for exported symbols that don't have well-defined prefixes.
Signed-off-by: Christian Heimes <christian@python.org>