pgsql: Introduce a SQL-callable function array_sort(anyarray).

Introduce a SQL-callable function array_sort(anyarray).

Create a function that will sort the elements of an array
according to the element type's sort order. If the array
has more than one dimension, the sub-arrays of the first
dimension are sorted per normal array-comparison rules,
leaving their contents alone.

In support of this, add pg_type.typarray to the set of fields
cached by the typcache.

Author: Junwang Zhao <zhjwpku(at)gmail(dot)com>
Co-authored-by: Jian He <jian(dot)universality(at)gmail(dot)com>
Reviewed-by: Aleksander Alekseev <aleksander(at)timescale(dot)com>
Discussion: https://postgr.es/m/CAEG8a3J41a4dpw_-F94fF-JPRXYxw-GfsgoGotKcjs9LVfEEvw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6c12ae09f5a5d6c153eaea7901542591dc28fb9e

Modified Files
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doc/src/sgml/func.sgml | 36 +++++
src/backend/utils/adt/array_userfuncs.c | 178 +++++++++++++++++++++++++
src/backend/utils/cache/typcache.c | 2 +
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_proc.dat | 12 ++
src/include/utils/typcache.h | 1 +
src/test/regress/expected/arrays.out | 142 ++++++++++++++++++++
src/test/regress/expected/collate.icu.utf8.out | 13 ++
src/test/regress/sql/arrays.sql | 36 +++++
src/test/regress/sql/collate.icu.utf8.sql | 4 +
src/tools/pgindent/typedefs.list | 1 +
11 files changed, 426 insertions(+), 1 deletion(-)