Preserve tz when converting to jsonb timestamptz
This removes an inconsistency in the treatment of different datatypes by
the jsonpath timestamp_tz() function. Conversions from data types that
are not timestamp-aware, such as date and timestamp, are now treated
consistently with conversion from those that are such as timestamptz.
Author: David Wheeler
Reviewed-by: Junwang Zhao and Jeevan Chalke
Discussion: http://postgr.es/m/
7DE080CE-6D8C-4794-9BD1-
7D9699172FAB%40justatheory.com
Backpatch to release 17.