Enforce RETURNING typmod for empty-set JSON_ARRAY(query)

Fix JSON_ARRAY(query) empty set handling and view deparsing

Fix integer overflow in nodeWindowAgg.c

Update .abi-compliance-history for AddRelationNotNullConstraints().

Avoid name collision with NOT NULL constraints

Fix computation of varnullingrels when translating appendrel Var

Simplify creation of built-in functions with default arguments.

Fix the volatility setting of json{b}_strip_nulls

Suppress new "may be used uninitialized" warning.

pg_mblen_range, pg_mblen_with_len: Valgrind after encoding ereport.

Fix SUBSTRING() for toasted multibyte characters.