pgsql: CLUSTER specified the wrong namespace when renaming toast tables

Log Message:
-----------
CLUSTER specified the wrong namespace when renaming toast tables of temporary
relations (they don't live in pg_toast). This caused an Assert failure in
assert-enabled builds. So far as I can see, in a non-assert build it would
only have messed up the checks for conflicting names, so a failure would be
quite improbable but perhaps not impossible.

Tags:
----
REL8_4_STABLE

Modified Files:
--------------
pgsql/src/backend/commands:
cluster.c (r1.186 -> r1.186.2.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/cluster.c?r1=1.186&r2=1.186.2.1)
pgsql/src/test/regress/expected:
cluster.out (r1.20 -> r1.20.4.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/cluster.out?r1=1.20&r2=1.20.4.1)
pgsql/src/test/regress/sql:
cluster.sql (r1.12 -> r1.12.4.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/cluster.sql?r1=1.12&r2=1.12.4.1)