Inline memset() as MemSet().

src/backend/access/common/heaptuple.c

src/backend/access/common/indextuple.c

src/backend/access/common/tupdesc.c

src/backend/access/gist/gist.c

src/backend/access/hash/hashovfl.c

src/backend/access/hash/hashpage.c

src/backend/access/nbtree/nbtpage.c

src/backend/access/nbtree/nbtsort.c

src/backend/access/nbtree/nbtutils.c

src/backend/access/rtree/rtproc.c

src/backend/access/rtree/rtree.c

src/backend/bootstrap/bootstrap.c

src/backend/catalog/heap.c

src/backend/catalog/index.c

src/backend/catalog/pg_aggregate.c

src/backend/catalog/pg_operator.c

src/backend/catalog/pg_proc.c

src/backend/catalog/pg_type.c

src/backend/commands/defind.c

src/backend/commands/explain.c