Merge branch 'rb/hpe'

Portability updates for the HPE NonStop platform.

* rb/hpe:
compat/regex/regcomp.c: define intptr_t and uintptr_t on NonStop
git-compat-util.h: add FLOSS headers for HPE NonStop
config.mak.uname: support for modern HPE NonStop config.
transport-helper: drop read/write errno checks
transport-helper: use xread instead of read

diff --cc config.mak.uname
Simple merge

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

diff --cc transport-helper.c
Simple merge