Reducing more keyword conflicts

contrib/cube/cube.c

contrib/dblink/dblink.c

contrib/file_fdw/file_fdw.c

contrib/hstore/hstore_compat.c

contrib/intarray/_int_bool.c

contrib/intarray/_int_gist.c

contrib/intarray/_int_tool.c

contrib/isn/EAN13.h

contrib/isn/isn.c

contrib/lo/lo.c

contrib/ltree/ltxtquery_io.c

contrib/passwordcheck/passwordcheck.c

contrib/pg_stat_statements/pg_stat_statements.c

contrib/pg_trgm/trgm_regexp.c

contrib/pgcrypto/fortuna.c

contrib/pgcrypto/imath.c

contrib/pgcrypto/pgp-decrypt.c

contrib/pgstattuple/pgstatapprox.c

contrib/postgres_fdw/connection.c

contrib/postgres_fdw/postgres_fdw.c