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
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/0e551533b46069ec3b909ce5159eed51b768ca52

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