meson: pgxs Makefile.global differences

I started digging into a warning I noticed on my FDW builds where
Postgres is built with meson, e.g.
<https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=crake&dt=2023-08-16%2018%3A37%3A25&stg=FileTextArrayFDW-build>
which has this:

cc1: warning: ‘-Wformat-security’ ignored without ‘-Wformat’
[-Wformat-security]

I found that the pgxs Makefile.global built under meson is a bit
different. On debug builds for both this is what I get on HEAD (meson)
and REL_15_STABLE (autoconf), stripped of the current components:

         HEAD: CFLAGS =-Wshadow=compatible-local
REL_15_STABLE: CFLAGS =-Wall  -g

The warning is apparently due to the missing -Wall.

Shouldn't we be aiming for pretty much identical settings?

cheers

andrew

--
Andrew Dunstan
EDB:https://www.enterprisedb.com