Issue #15587: merge from 3.3

diff --cc Misc/NEWS
index 05a3647dbe9c8ff1ac91dba72ea74fb578eabdbe,47a5f4cbad55071e90eefe15ae6865d4394686d9..ba645e8946848fae88a6891510925af818f6e134
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -847,6 -620,16 +847,10 @@@ Buil
  - Issue #15819: Make sure we can build Python out-of-tree from a read-only
    source directory.  (Somewhat related to issue #9860.)
  
 -Tools/Demos
 ------------
 -
 -- Issue #13301: use ast.literal_eval() instead of eval() in Tools/i18n/msgfmt.py
 -  Patch by Serhiy Storchaka.
 -
+ - Issue #15587: Enable Tk high-resolution text rendering on Macs with
+   Retina displays.  Applies to Tkinter apps, such as IDLE, on OS X
+   framework builds linked with Cocoa Tk 8.5.
+ 
  Documentation
  -------------