pgsql: Pull up ANY-SUBLINK with the necessary lateral support.

Pull up ANY-SUBLINK with the necessary lateral support.

For ANY-SUBLINK, we adopted a two-stage pull-up approach to handle
different types of scenarios. In the first stage, the sublink is pulled up
as a subquery. Because of this, when writing this code, we did not have
the ability to perform lateral joins, and therefore, we were unable to
pull up Var with varlevelsup=1. Now that we have the ability to use
lateral joins, we can eliminate this limitation.

Author: Andy Fan <zhihui.fan1213@gmail.com>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Reviewed-by: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Alena Rybakina <lena.ribackina@yandex.ru>
Reviewed-by: Andrey Lepikhov <a.lepikhov@postgrespro.ru>

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/9f133763961e280d8ba692bcad0b061b861e9138

Modified Files
--------------
contrib/postgres_fdw/expected/postgres_fdw.out |   6 +-
contrib/postgres_fdw/sql/postgres_fdw.sql      |   4 +-
src/backend/optimizer/plan/subselect.c         |  17 +++-
src/test/regress/expected/join.out             |  14 +--
src/test/regress/expected/subselect.out        | 126 +++++++++++++++++++++++++
src/test/regress/sql/join.sql                  |   8 +-
src/test/regress/sql/subselect.sql             |  37 ++++++++
7 files changed, 192 insertions(+), 20 deletions(-)