Add pg_statistic index, add missing Hiroshi file.

src/backend/catalog/aclchk.c

src/backend/catalog/indexing.c

src/backend/commands/comment.c

src/backend/commands/dbcommands.c

src/backend/commands/user.c

src/backend/rewrite/locks.c

src/backend/utils/adt/acl.c

src/backend/utils/adt/ruleutils.c

src/backend/utils/cache/syscache.c

src/backend/utils/init/miscinit.c

src/backend/utils/misc/superuser.c

src/include/catalog/catversion.h

src/include/catalog/indexing.h

src/include/executor/nodeTidscan.h

src/include/utils/syscache.h