Thread: [COMMITTERS] pgsql: Sync our copy of the timezone library with IANA releasetzcode20

Sync our copy of the timezone library with IANA release tzcode2017b.

zic no longer mishandles some transitions in January 2038 when it
attempts to work around Qt bug 53071.  This fixes a bug affecting
Pacific/Tongatapu that was introduced in zic 2016e.  localtime.c
now contains a workaround, useful when loading a file generated by
a buggy zic.

There are assorted cosmetic changes as well, notably relocation
of a bunch of #defines.

Branch
------
REL9_6_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/6872d96a3bb893c987a3df623754c13deac8254f

Modified Files
--------------
src/timezone/README      |  2 +-
src/timezone/localtime.c | 73 +++++++++++++++++++++++++++++++++++-----------
src/timezone/pgtz.c      |  9 +++---
src/timezone/private.h   | 76 ++++++++++++++++++++++++++++++++++++------------
src/timezone/strftime.c  | 11 +++++--
src/timezone/tzfile.h    | 52 ---------------------------------
src/timezone/zic.c       | 15 ++++++++--
7 files changed, 139 insertions(+), 99 deletions(-)