Merge branch 'fc/macos-x-clipped-write' into maint

Mac OS X does not like to write(2) more than INT_MAX number of
bytes; work it around by chopping write(2) into smaller pieces.

* fc/macos-x-clipped-write:
  compate/clipped-write.c: large write(2) fails on Mac OS X/XNU

diff --cc Makefile
Simple merge

diff --cc config.mak.uname
Simple merge

diff --cc git-compat-util.h
Simple merge