Rename _Py_DumpTraceback and _Py_DumpTracebackThreads to
:c:func:`PyUnstable_DumpTraceback` and
:c:func:`PyUnstable_DumpTracebackThreads`.
Rename _Py_DumpTraceback and _Py_DumpTracebackThreads to
:c:func:`PyUnstable_DumpTraceback` and
:c:func:`PyUnstable_DumpTracebackThreads`.