Merge with 3.6

diff --cc Misc/NEWS
index 088dfa941d1dd5b07973c637bb87b23d478dc7b1,f9e247425e29427afcc6a9b1d2aa04d9ccab165b..90dfc5fa6829b41ad4b2d7c3f668d079c4eb37cd
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,12 -10,8 +10,14 @@@ What's New in Python 3.7.0 alpha 
  Core and Builtins
  -----------------
  
+ - Issue #28192: Don't import readline in isolated mode.
+ 
 +- Issue #27441: Remove some redundant assignments to ob_size in longobject.c.
 +  Thanks Oren Milman.
 +
 +- Issue #27222: Clean up redundant code in long_rshift function. Thanks
 +  Oren Milman.
 +
  - Upgrade internal unicode databases to Unicode version 9.0.0.
  
  - Issue #28131: Fix a regression in zipimport's compile_source().  zipimport