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_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/f56c42e503a565333f9e77d0ea40d70ecc152af8

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