bpo-35497: add versionadded tag for EPOLLEXCLUSIVE (GH-11162)

(cherry picked from commit 92330c0b6d6c253c41a133cc50caea4853c7e311)

Co-authored-by: Manjusaka <lizheao940510@gmail.com>
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 955ac2a..5b8fd7e 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -317,6 +317,9 @@
    | :const:`EPOLLMSG`       | Ignored.                                      |
    +-------------------------+-----------------------------------------------+
 
+   .. versionadded:: 3.6
+      :const:`EPOLLEXCLUSIVE` was added.  It's only supported by Linux Kernel 4.5
+      or later.
 
 .. method:: epoll.close()