pgsql: Extend the BKI infrastructure to allow system catalogs to be

Log Message:
-----------
Extend the BKI infrastructure to allow system catalogs to be given
hand-assigned rowtype OIDs, even when they are not "bootstrapped" catalogs
that have handmade type rows in pg_type.h. Give pg_database such an OID.
Restore the availability of C macros for the rowtype OIDs of the bootstrapped
catalogs. (These macros are now in the individual catalogs' .h files,
though, not in pg_type.h.)

This commit doesn't do anything especially useful by itself, but it's
necessary infrastructure for reverting some ill-considered changes in
relcache.c.

Modified Files:
--------------
pgsql/doc/src/sgml:
bki.sgml (r1.21 -> r1.22)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/bki.sgml?r1=1.21&r2=1.22)
pgsql/src/backend/bootstrap:
bootparse.y (r1.97 -> r1.98)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootparse.y?r1=1.97&r2=1.98)
bootscanner.l (r1.48 -> r1.49)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/bootstrap/bootscanner.l?r1=1.48&r2=1.49)
pgsql/src/backend/catalog:
genbki.sh (r1.46 -> r1.47)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/genbki.sh?r1=1.46&r2=1.47)
heap.c (r1.358 -> r1.359)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/heap.c?r1=1.358&r2=1.359)
toasting.c (r1.18 -> r1.19)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/toasting.c?r1=1.18&r2=1.19)
pgsql/src/backend/commands:
cluster.c (r1.186 -> r1.187)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/cluster.c?r1=1.186&r2=1.187)
tablecmds.c (r1.298 -> r1.299)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablecmds.c?r1=1.298&r2=1.299)
pgsql/src/backend/executor:
execMain.c (r1.327 -> r1.328)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/executor/execMain.c?r1=1.327&r2=1.328)
pgsql/src/include/catalog:
catversion.h (r1.539 -> r1.540)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.539&r2=1.540)
duplicate_oids (r1.8 -> r1.9)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/duplicate_oids?r1=1.8&r2=1.9)
genbki.h (r1.3 -> r1.4)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/genbki.h?r1=1.3&r2=1.4)
heap.h (r1.92 -> r1.93)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/heap.h?r1=1.92&r2=1.93)
pg_attribute.h (r1.152 -> r1.153)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_attribute.h?r1=1.152&r2=1.153)
pg_class.h (r1.115 -> r1.116)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_class.h?r1=1.115&r2=1.116)
pg_database.h (r1.49 -> r1.50)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_database.h?r1=1.49&r2=1.50)
pg_proc.h (r1.550 -> r1.551)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.550&r2=1.551)
pg_type.h (r1.209 -> r1.210)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_type.h?r1=1.209&r2=1.210)
unused_oids (r1.8 -> r1.9)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/unused_oids?r1=1.8&r2=1.9)
pgsql/src/tools/msvc:
Genbki.pm (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/Genbki.pm?r1=1.6&r2=1.7)