Silence compiler warning in assertion-enabled builds.
Silence compiler warning in assertion-enabled builds.

With -Wtype-limits, gcc correctly points out that size_t can never be < 0.
Backpatch to 9.3 and 9.2. It's been like this forever, but in <= 9.1 you got
a lot other warnings with -Wtype-limits anyway (at least with my version of
gcc).

Andres Freund

greenplum-db/gpdb,pavanvd/postgres-xl,ashwinstar/gpdb,adam8157/gpdb,ashwinstar/gpdb,ovr/postgres-xl,Postgres-XL/Postgres-XL,xinzweb/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,yazun/postgres-xl,ovr/postgres-xl,lisakowen/gpdb,greenplum-db/gpdb,lisakowen/gpdb,greenplum-db/gpdb,zeroae/postgres-xl,lisakowen/gpdb,jmcatamney/gpdb,ovr/postgres-xl,yazun/postgres-xl,lisakowen/gpdb,ashwinstar/gpdb,50wu/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,50wu/gpdb,adam8157/gpdb,xinzweb/gpdb,zeroae/postgres-xl,lisakowen/gpdb,xinzweb/gpdb,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,techdragon/Postgres-XL,oberstet/postgres-xl,techdragon/Postgres-XL,zeroae/postgres-xl,50wu/gpdb,adam8157/gpdb,xinzweb/gpdb,greenplum-db/gpdb,adam8157/gpdb,lisakowen/gpdb,50wu/gpdb,yazun/postgres-xl,jmcatamney/gpdb,greenplum-db/gpdb,adam8157/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,xinzweb/gpdb,ashwinstar/gpdb,50wu/gpdb,xinzweb/gpdb,jmcatamney/gpdb,adam8157/gpdb,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,ovr/postgres-xl,Postgres-XL/Postgres-XL,yazun/postgres-xl,ashwinstar/gpdb,lisakowen/gpdb,oberstet/postgres-xl,yazun/postgres-xl,ashwinstar/gpdb,50wu/gpdb,lisakowen/gpdb,pavanvd/postgres-xl,ashwinstar/gpdb,adam8157/gpdb,xinzweb/gpdb,oberstet/postgres-xl,50wu/gpdb,zeroae/postgres-xl,pavanvd/postgres-xl,Postgres-XL/Postgres-XL,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,techdragon/Postgres-XL,zeroae/postgres-xl,ovr/postgres-xl,oberstet/postgres-xl,pavanvd/postgres-xl,jmcatamney/gpdb,adam8157/gpdb