(Merge 3.1) Issue #11277: mmap.mmap() calls fcntl(fd, F_FULLFSYNC) on Mac OS X

to get around a mmap bug with sparse files. Patch written by Steffen Daode
Nurpmeso.

diff --cc Doc/library/mmap.rst
Simple merge

diff --cc Lib/test/test_zlib.py
Simple merge

diff --cc Misc/NEWS
index 592223348ce1c64d7aca58c6d984096a1e650423,887861261fde986743cd2b9f046f2cc410ac03fa..2a500949bc18fc81a79cf7a12bb4feb12a485be1
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -79,11 -66,9 +79,14 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #11277: mmap.mmap() calls fcntl(fd, F_FULLFSYNC) on Mac OS X to get
+   around a mmap bug with sparse files. Patch written by Steffen Daode Nurpmeso.
+ 
 +- Issue #11858: configparser.ExtendedInterpolation expected lower-case section
 +  names.
 +
 +- Issue #11324: ConfigParser(interpolation=None) now works correctly.
 +
  - Issue #11763: don't use difflib in TestCase.assertMultiLineEqual if the
    strings are too long.
  

diff --cc Modules/mmapmodule.c
Simple merge