pgsql: meson: Add headerscheck and cpluspluscheck targets

meson: Add headerscheck and cpluspluscheck targets

Author: Miłosz Bieniek <bieniek.milosz0@gmail.com>
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Bilal Yavuz <byavuz81@gmail.com>
Discussion:
https://www.postgresql.org/message-id/flat/CAMSWrt-PoQt4sHryWrB1ViuGBJF_PpbjoSGrWR2Ry47bHNLDqg%40mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/e82fc27e095b5a84c578b6e6b43b3396463bd812

Modified Files
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doc/src/sgml/targets-meson.txt |  2 ++
meson.build                    | 15 +++++++++++++++
src/tools/pginclude/README     |  6 ++++++
3 files changed, 23 insertions(+)