pgsql: Add LZ4 compression to pg_dump

Add LZ4 compression to pg_dump

Expand pg_dump's compression streaming and file APIs to support the lz4
algorithm. The newly added compress_lz4.{c,h} files cover all the
functionality of the aforementioned APIs. Minor changes were necessary
in various pg_backup_* files, where code for the 'lz4' file suffix has
been added, as well as pg_dump's compression option parsing.

Author: Georgios Kokolatos
Reviewed-by: Michael Paquier, Rachel Heaton, Justin Pryzby, Shi Yu, Tomas Vondra
Discussion:
https://postgr.es/m/faUNEOpts9vunEaLnmxmG-DldLSg_ql137OC3JYDmgrOMHm1RvvWY2IdBkv_CRxm5spCCb_OmKNk2T03TMm0fBEWveFF9wA1WizPuAgB7Ss%3D%40protonmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/0da243fed0875932f781aff08df782b56af58d02

Modified Files
--------------
doc/src/sgml/ref/pg_dump.sgml         |  13 +-
src/bin/pg_dump/Makefile              |   2 +
src/bin/pg_dump/compress_io.c         |  26 +-
src/bin/pg_dump/compress_lz4.c        | 626 ++++++++++++++++++++++++++++++++++
src/bin/pg_dump/compress_lz4.h        |  24 ++
src/bin/pg_dump/meson.build           |   8 +-
src/bin/pg_dump/pg_backup_archiver.c  |   6 +-
src/bin/pg_dump/pg_backup_directory.c |   9 +-
src/bin/pg_dump/pg_dump.c             |   5 +-
src/bin/pg_dump/t/002_pg_dump.pl      |  82 ++++-
src/tools/pginclude/cpluspluscheck    |   1 +
src/tools/pgindent/typedefs.list      |   2 +
12 files changed, 782 insertions(+), 22 deletions(-)