Inline some small functions called for every row.

src/backend/access/transam/xid.c

src/backend/executor/execTuples.c

src/backend/executor/nodeTee.c

src/backend/storage/buffer/bufmgr.c

src/backend/storage/page/bufpage.c

src/backend/utils/time/tqual.c

src/include/access/xact.h

src/include/executor/executor.h

src/include/storage/bufmgr.h

src/include/storage/bufpage.h

src/include/utils/tqual.h