bpo-45296: Fix exit/quit message on Windows (GH-28577) (GH-28600)

IDLE recognizes Ctrl-D, as on other systems, instead of Ctrl-Z.
(cherry picked from commit e649e0658ff2af87b07d994c05ae048e16e31aae)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>
diff --git a/Lib/idlelib/pyshell.py b/Lib/idlelib/pyshell.py
index 4e74400..6c333b0 100755
--- a/Lib/idlelib/pyshell.py
+++ b/Lib/idlelib/pyshell.py
@@ -66,6 +66,13 @@
 HOST = '127.0.0.1' # python execution server on localhost loopback
 PORT = 0  # someday pass in host, port for remote debug capability
 
+try:  # In case IDLE started with -n.
+    eof = 'Ctrl-D (end-of-file)'
+    exit.eof = eof
+    quit.eof = eof
+except NameError: # In case python started with -S.
+    pass
+
 # Override warnings module to write to warning_stream.  Initialize to send IDLE
 # internal warnings to the console.  ScriptBinding.check_syntax() will
 # temporarily redirect the stream to the shell window to display warnings when