Tweak previous patch to ensure edata->filename always gets initialized.
Tweak previous patch to ensure edata->filename always gets initialized.

On a platform that isn't supplying __FILE__, previous coding would either
crash or give a stale result for the filename string.  Not sure how likely
that is, but the original code catered for it, so let's keep doing so.

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