pgsql: Stamp HEAD as 19devel.

Stamp HEAD as 19devel.

Let the hacking begin ...

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/2652835d3efa003439ecc23d5fc3cf089c5952a6

Modified Files
--------------
configure                    |   18 +-
configure.ac                 |    2 +-
doc/src/sgml/filelist.sgml   |    2 +-
doc/src/sgml/release-18.sgml | 4200 ------------------------------------------
doc/src/sgml/release-19.sgml |   16 +
doc/src/sgml/release.sgml    |    2 +-
meson.build                  |    2 +-
src/tools/git_changelog      |    1 +
src/tools/version_stamp.pl   |    2 +-
9 files changed, 31 insertions(+), 4214 deletions(-)