Fixes #11088: IDLE crashes when using F5 to run a script on OSX with Tk 8.5

Without this patch IDLE will crash reliably on OSX when Tkinter
is linked to TkCocoa 8.5.x.

To reproduce:

* Create a new file (script.py) with the following two lines:

x = input('prompt: ')
print(x)

* Save the script

* Run the script using the F5 keyboard shortcut
  (running from the menu works fine)

The patch is a fairly crude hack, but we haven't found a better
workaround for this Tk bug yet.
diff --git a/Misc/NEWS b/Misc/NEWS
index 7db72e7..c40136c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -23,6 +23,9 @@
 Library
 -------
 
+- Issue #11088: don't crash when using F5 to run a script in IDLE on MacOSX
+  with Tk 8.5.
+
 - Issue #9516: Issue #9516: avoid errors in sysconfig when MACOSX_DEPLOYMENT_TARGET
   is set in shell.