Issue #21958: Merge with 3.4

diff --cc Misc/NEWS
index 3f49d9c9ac1bdcaaf9b433d125f53329719855fa,8d32544ad59b7f382346a80f0b6278620b799fe4..f1db374a54050125078c31cbab453ec4b8495ef6
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -664,25 -553,7 +664,28 @@@ IDL
  Build
  -----
  
 -- The Windows build now includes OpenSSL 1.0.1g
++- Issue #21958: Define HAVE_ROUND when building with Visual Studio 2013 and
++  above.  Patch by Zachary Turner.
++
 +- Issue #18093: the programs that embed the CPython runtime are now in a
 +  separate "Programs" directory, rather than being kept in the Modules
 +  directory.
 +
 +- Issue #15759: "make suspicious", "make linkcheck" and "make doctest" in Doc/
 +  now display special message when and only when there are failures.
 +
 +- Issue #21141: The Windows build process no longer attempts to find Perl,
 +  instead relying on OpenSSL source being configured and ready to build.  The
 +  ``PCbuild\build_ssl.py`` script has been re-written and re-named to
 +  ``PCbuild\prepare_ssl.py``, and takes care of configuring OpenSSL source
 +  for both 32 and 64 bit platforms.  OpenSSL sources obtained from
 +  svn.python.org will always be pre-configured and ready to build.
 +
 +- Issue #21037: Add a build option to enable AddressSanitizer support.
 +
 +- Issue #19962: The Windows build process now creates "python.bat" in the
 +  root of the source tree, which passes all arguments through to the most
 +  recently built interpreter.
  
  - Issue #21285: Refactor and fix curses configure check to always search
    in a ncursesw directory.

diff --cc PC/pyconfig.h
Simple merge