pgsql: Upgrade formrdesc() so that it can correctly initialize the

Log Message:
-----------
Upgrade formrdesc() so that it can correctly initialize the tupledesc
(rd_att) field of a nailed-in-cache relcache entry. This fixes the bug
reported by Alvaro 8-Dec-2004; I believe it probably also explains
Grant Finnemore's report of 10-Sep-2004.

In an unrelated change in the same file, put back 7.4's response to
failure to rename() the relcache init file, ie, unlink the useless
temp file. I did not put back the warning message, since there might
actually be some reason not to have that.

Modified Files:
--------------
pgsql/src/backend/utils/cache:
relcache.c (r1.212 -> r1.213)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/relcache.c.diff?r1=1.212&r2=1.213)
pgsql/src/include/catalog:
pg_type.h (r1.156 -> r1.157)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_type.h.diff?r1=1.156&r2=1.157)