Обсуждение: pgsql: Sync our copy of the timezone library with IANA release tzcode20

Sync our copy of the timezone library with IANA release tzcode2020d.

There's no functional change at all here, but I'm curious to see
whether this change successfully shuts up Coverity's warning about
a useless strcmp(), which appeared with the previous update.

Discussion: http://mm.icann.org/pipermail/tz/2020-October/029370.html

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/c5054da0d7ee59a93ca6d7f7fc669ef0210dbad3

Modified Files
--------------
src/timezone/README |  2 +-
src/timezone/zic.c  | 14 ++++++++++++--
2 files changed, 13 insertions(+), 3 deletions(-)