SF "bug" 115973:  patches from Norman Vine so that shared libraries and
Tkinter work under Cygwin.  Accepted on faith & reasonableness.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 34360fe..0a3b74b 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -57,7 +57,7 @@
 #include <Menus.h>
 #endif
 
-#if !defined(MS_WINDOWS)
+#if !(defined(MS_WINDOWS) || defined(__CYGWIN__))
 #define HAVE_CREATEFILEHANDLER
 #endif