Add void * cast to MemSet to silence compiler, and add comment that we already check for alignment.
Add void * cast to MemSet to silence compiler, and add comment that we
already check for alignment.

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