Volatile-ize all five places where we expect a PG_TRY block to restore old memory context in plpython.  Before only one of them was marked volatile, but per report from Zdenek Kotala, some compilers do the wrong thing here.
Volatile-ize all five places where we expect a PG_TRY block to restore
old memory context in plpython.  Before only one of them was marked
volatile, but per report from Zdenek Kotala, some compilers do the
wrong thing here.

xinzweb/gpdb,greenplum-db/gpdb,Postgres-XL/Postgres-XL,xinzweb/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,lisakowen/gpdb,pavanvd/postgres-xl,arcivanov/postgres-xl,snaga/postgres-xl,yazun/postgres-xl,50wu/gpdb,arcivanov/postgres-xl,oberstet/postgres-xl,adam8157/gpdb,ashwinstar/gpdb,zeroae/postgres-xl,arcivanov/postgres-xl,postmind-net/postgres-xl,arcivanov/postgres-xl,ovr/postgres-xl,lisakowen/gpdb,adam8157/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,ovr/postgres-xl,yazun/postgres-xl,tpostgres-projects/tPostgres,postmind-net/postgres-xl,arcivanov/postgres-xl,zeroae/postgres-xl,Postgres-XL/Postgres-XL,ashwinstar/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,lisakowen/gpdb,50wu/gpdb,adam8157/gpdb,adam8157/gpdb,lisakowen/gpdb,tpostgres-projects/tPostgres,tpostgres-projects/tPostgres,adam8157/gpdb,postmind-net/postgres-xl,ashwinstar/gpdb,greenplum-db/gpdb,tpostgres-projects/tPostgres,adam8157/gpdb,techdragon/Postgres-XL,ovr/postgres-xl,50wu/gpdb,pavanvd/postgres-xl,oberstet/postgres-xl,pavanvd/postgres-xl,ovr/postgres-xl,Postgres-XL/Postgres-XL,snaga/postgres-xl,lisakowen/gpdb,zeroae/postgres-xl,adam8157/gpdb,kmjungersen/PostgresXL,kmjungersen/PostgresXL,xinzweb/gpdb,jmcatamney/gpdb,xinzweb/gpdb,xinzweb/gpdb,snaga/postgres-xl,ashwinstar/gpdb,lisakowen/gpdb,Postgres-XL/Postgres-XL,jmcatamney/gpdb,adam8157/gpdb,arcivanov/postgres-xl,yazun/postgres-xl,yazun/postgres-xl,kmjungersen/PostgresXL,50wu/gpdb,postmind-net/postgres-xl,oberstet/postgres-xl,zeroae/postgres-xl,greenplum-db/gpdb,snaga/postgres-xl,kmjungersen/PostgresXL,pavanvd/postgres-xl,snaga/postgres-xl,techdragon/Postgres-XL,50wu/gpdb,lisakowen/gpdb,50wu/gpdb,yazun/postgres-xl,xinzweb/gpdb,jmcatamney/gpdb,50wu/gpdb,greenplum-db/gpdb,kmjungersen/PostgresXL,greenplum-db/gpdb,pavanvd/postgres-xl,oberstet/postgres-xl,tpostgres-projects/tPostgres,Postgres-XL/Postgres-XL,xinzweb/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,ashwinstar/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,ovr/postgres-xl,lisakowen/gpdb,postmind-net/postgres-xl,50wu/gpdb,zeroae/postgres-xl,xinzweb/gpdb