Issue #25221: merge from 3.5.

diff --cc Misc/NEWS
index b0db3a28aa9d3072b6b7e48acdb6e9f6d40dc0cf,f728c3660c339fe0d3845b8a6748299d4129702a..7d89170741a9fa4b86fead098c4b11706bd892e0
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -10,20 -10,8 +10,23 @@@ What's New in Python 3.6.0 beta 
  Core and Builtins
  -----------------
  
 -- Issue #25221: Fix corrupted result from PyLong_FromLong(0) when
 -  Python is compiled with NSMALLPOSINTS = 0.
++- Issue #25221: Fix corrupted result from PyLong_FromLong(0) when Python
++  is compiled with NSMALLPOSINTS = 0.
++
 +- Issue #27080: Implement formatting support for PEP 515.  Initial patch
 +  by Chris Angelico.
 +
 +- Issue #27199: In tarfile, expose copyfileobj bufsize to improve throughput.
 +  Patch by Jason Fried.
 +
 +- Issue #27948: In f-strings, only allow backslashes inside the braces
 +  (where the expressions are).  This is a breaking change from the 3.6
 +  alpha releases, where backslashes are allowed anywhere in an
 +  f-string.  Also, require that expressions inside f-strings be
 +  enclosed within literal braces, and not escapes like
 +  f'\x7b"hi"\x7d'.
 +
 +- Issue #28046: Remove platform-specific directories from sys.path.
  
  - Issue #25758: Prevents zipimport from unnecessarily encoding a filename
    (patch by Eryk Sun)

diff --cc Objects/longobject.c
Simple merge