Issue #16241: document -X faulthandler command line option.
Patch by Marek Šuppa.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index dbe6c47..2703684 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -358,7 +358,8 @@
.. cmdoption:: -X
Reserved for various implementation-specific options. CPython currently
- defines none of them, but allows to pass arbitrary values and retrieve
+ defines just one, you can use ``-X faulthander`` to enable
+ :data:`faulthandler`. It also allows to pass arbitrary values and retrieve
them through the :data:`sys._xoptions` dictionary.
.. versionchanged:: 3.2