Some changes to prepare for LONG attributes.

src/backend/access/common/heaptuple.c

src/backend/access/heap/heapam.c

src/backend/bootstrap/bootstrap.c

src/backend/catalog/heap.c

src/backend/catalog/index.c

src/backend/catalog/indexing.c

src/backend/catalog/pg_operator.c

src/backend/catalog/pg_type.c

src/backend/commands/async.c

src/backend/commands/cluster.c

src/backend/commands/command.c

src/backend/commands/comment.c

src/backend/commands/copy.c

src/backend/commands/creatinh.c

src/backend/commands/indexcmds.c

src/backend/commands/proclang.c

src/backend/commands/remove.c

src/backend/commands/rename.c

src/backend/commands/trigger.c

src/backend/commands/vacuum.c