Fix bugs in the COPY heap-insert batching patch.
Fix bugs in the COPY heap-insert batching patch.

Forgot to call RestoreBkpBlocks() in the redo-function, as pointed out by
Simon Riggs. In redo of a regular heap insert, it's taken care of in
heap_redo(), but this new record type uses the heap2 RM, and heap2_redo()
does not take care of that for you.

Also, failed to reset the vmbuffer and all_visibile_cleared local variables
after switching to a new buffer.

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