Repair memory leakage introduced into the non-hashed aggregate case by 7.4 rewrite for hashed aggregate support.  If the transition data type is pass-by-reference, the transValue must be pfreed when starting a new group boundary, else we have a one-value-per-group leakage.  Thanks to Rae Steining for providing a reproducible test case.
Repair memory leakage introduced into the non-hashed aggregate case by
7.4 rewrite for hashed aggregate support.  If the transition data type
is pass-by-reference, the transValue must be pfreed when starting a new
group boundary, else we have a one-value-per-group leakage.  Thanks to
Rae Steining for providing a reproducible test case.

kmjungersen/PostgresXL,chrishajas/gpdb,zeroae/postgres-xl,kaknikhil/gpdb,lisakowen/gpdb,tangp3/gpdb,greenplum-db/gpdb,tpostgres-projects/tPostgres,royc1/gpdb,adam8157/gpdb,atris/gpdb,postmind-net/postgres-xl,lpetrov-pivotal/gpdb,rubikloud/gpdb,ashwinstar/gpdb,chrishajas/gpdb,edespino/gpdb,zeroae/postgres-xl,xinzweb/gpdb,zeroae/postgres-xl,randomtask1155/gpdb,kaknikhil/gpdb,atris/gpdb,lpetrov-pivotal/gpdb,lintzc/gpdb,yazun/postgres-xl,lpetrov-pivotal/gpdb,rubikloud/gpdb,ovr/postgres-xl,janebeckman/gpdb,Quikling/gpdb,chrishajas/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,ahachete/gpdb,techdragon/Postgres-XL,janebeckman/gpdb,tangp3/gpdb,ahachete/gpdb,rvs/gpdb,Postgres-XL/Postgres-XL,ovr/postgres-xl,ovr/postgres-xl,yuanzhao/gpdb,greenplum-db/gpdb,xuegang/gpdb,kaknikhil/gpdb,edespino/gpdb,rvs/gpdb,Chibin/gpdb,zaksoup/gpdb,kaknikhil/gpdb,tangp3/gpdb,Postgres-XL/Postgres-XL,tpostgres-projects/tPostgres,atris/gpdb,edespino/gpdb,rvs/gpdb,kaknikhil/gpdb,50wu/gpdb,Chibin/gpdb,rvs/gpdb,foyzur/gpdb,xinzweb/gpdb,50wu/gpdb,atris/gpdb,lpetrov-pivotal/gpdb,yuanzhao/gpdb,xuegang/gpdb,0x0FFF/gpdb,randomtask1155/gpdb,edespino/gpdb,zaksoup/gpdb,Chibin/gpdb,royc1/gpdb,greenplum-db/gpdb,edespino/gpdb,adam8157/gpdb,postmind-net/postgres-xl,atris/gpdb,xinzweb/gpdb,cjcjameson/gpdb,tpostgres-projects/tPostgres,janebeckman/gpdb,lisakowen/gpdb,cjcjameson/gpdb,zeroae/postgres-xl,ovr/postgres-xl,foyzur/gpdb,zaksoup/gpdb,xuegang/gpdb,kaknikhil/gpdb,chrishajas/gpdb,janebeckman/gpdb,lisakowen/gpdb,foyzur/gpdb,rvs/gpdb,50wu/gpdb,50wu/gpdb,randomtask1155/gpdb,Quikling/gpdb,CraigHarris/gpdb,adam8157/gpdb,rvs/gpdb,xinzweb/gpdb,Quikling/gpdb,rvs/gpdb,foyzur/gpdb,techdragon/Postgres-XL,CraigHarris/gpdb,lisakowen/gpdb,randomtask1155/gpdb,xuegang/gpdb,xinzweb/gpdb,0x0FFF/gpdb,ahachete/gpdb,arcivanov/postgres-xl,ahachete/gpdb,50wu/gpdb,arcivanov/postgres-xl,kaknikhil/gpdb,oberstet/postgres-xl,CraigHarris/gpdb,xinzweb/gpdb,ashwinstar/gpdb,rubikloud/gpdb,postmind-net/postgres-xl,arcivanov/postgres-xl,royc1/gpdb,yuanzhao/gpdb,tpostgres-projects/tPostgres,CraigHarris/gpdb,zaksoup/gpdb,Quikling/gpdb,lintzc/gpdb,rubikloud/gpdb,cjcjameson/gpdb,lintzc/gpdb,janebeckman/gpdb,foyzur/gpdb,CraigHarris/gpdb,lisakowen/gpdb,xinzweb/gpdb,zaksoup/gpdb,xuegang/gpdb,tangp3/gpdb,ashwinstar/gpdb,lpetrov-pivotal/gpdb,kmjungersen/PostgresXL,greenplum-db/gpdb,pavanvd/postgres-xl,yuanzhao/gpdb,adam8157/gpdb,adam8157/gpdb,foyzur/gpdb,0x0FFF/gpdb,foyzur/gpdb,50wu/gpdb,pavanvd/postgres-xl,xuegang/gpdb,arcivanov/postgres-xl,ashwinstar/gpdb,kmjungersen/PostgresXL,tangp3/gpdb,50wu/gpdb,Chibin/gpdb,Chibin/gpdb,rubikloud/gpdb,royc1/gpdb,Quikling/gpdb,royc1/gpdb,randomtask1155/gpdb,kmjungersen/PostgresXL,chrishajas/gpdb,kmjungersen/PostgresXL,lintzc/gpdb,yuanzhao/gpdb,ahachete/gpdb,kaknikhil/gpdb,Quikling/gpdb,snaga/postgres-xl,rubikloud/gpdb,rvs/gpdb,zaksoup/gpdb,cjcjameson/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,arcivanov/postgres-xl,postmind-net/postgres-xl,techdragon/Postgres-XL,0x0FFF/gpdb,jmcatamney/gpdb,Postgres-XL/Postgres-XL,janebeckman/gpdb,lpetrov-pivotal/gpdb,randomtask1155/gpdb,zaksoup/gpdb,xinzweb/gpdb,oberstet/postgres-xl,tangp3/gpdb,CraigHarris/gpdb,cjcjameson/gpdb,lintzc/gpdb,yuanzhao/gpdb,lintzc/gpdb,snaga/postgres-xl,tangp3/gpdb,atris/gpdb,lintzc/gpdb,0x0FFF/gpdb,pavanvd/postgres-xl,yazun/postgres-xl,randomtask1155/gpdb,adam8157/gpdb,Chibin/gpdb,royc1/gpdb,pavanvd/postgres-xl,ovr/postgres-xl,CraigHarris/gpdb,greenplum-db/gpdb,Chibin/gpdb,edespino/gpdb,lisakowen/gpdb,tangp3/gpdb,lintzc/gpdb,edespino/gpdb,janebeckman/gpdb,rubikloud/gpdb,arcivanov/postgres-xl,0x0FFF/gpdb,Quikling/gpdb,adam8157/gpdb,janebeckman/gpdb,oberstet/postgres-xl,cjcjameson/gpdb,yuanzhao/gpdb,Quikling/gpdb,50wu/gpdb,Quikling/gpdb,greenplum-db/gpdb,rvs/gpdb,snaga/postgres-xl,lisakowen/gpdb,foyzur/gpdb,jmcatamney/gpdb,CraigHarris/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,zeroae/postgres-xl,Postgres-XL/Postgres-XL,kaknikhil/gpdb,lpetrov-pivotal/gpdb,yazun/postgres-xl,ashwinstar/gpdb,snaga/postgres-xl,ahachete/gpdb,snaga/postgres-xl,chrishajas/gpdb,zaksoup/gpdb,chrishajas/gpdb,lpetrov-pivotal/gpdb,edespino/gpdb,Quikling/gpdb,jmcatamney/gpdb,randomtask1155/gpdb,yazun/postgres-xl,lintzc/gpdb,edespino/gpdb,atris/gpdb,cjcjameson/gpdb,oberstet/postgres-xl,ashwinstar/gpdb,janebeckman/gpdb,atris/gpdb,xuegang/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,yazun/postgres-xl,ahachete/gpdb,xuegang/gpdb,jmcatamney/gpdb,0x0FFF/gpdb,janebeckman/gpdb,techdragon/Postgres-XL,yuanzhao/gpdb,pavanvd/postgres-xl,tpostgres-projects/tPostgres,kaknikhil/gpdb,rvs/gpdb,adam8157/gpdb,rubikloud/gpdb,oberstet/postgres-xl,edespino/gpdb,CraigHarris/gpdb,Chibin/gpdb,chrishajas/gpdb,0x0FFF/gpdb,Chibin/gpdb,ashwinstar/gpdb,royc1/gpdb,Chibin/gpdb,cjcjameson/gpdb,ahachete/gpdb,Postgres-XL/Postgres-XL,royc1/gpdb,postmind-net/postgres-xl,greenplum-db/gpdb,lisakowen/gpdb,xuegang/gpdb