Reorder code so that we don't have to hold a critical section while reserving SLRU space for a new MultiXact.  The original coding would have treated out-of-disk-space as a PANIC condition, which is unnecessary.
Reorder code so that we don't have to hold a critical section while
reserving SLRU space for a new MultiXact.  The original coding would have
treated out-of-disk-space as a PANIC condition, which is unnecessary.

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