pgsql: Repair possible failure to update hint bits back to disk, per

Log Message:
-----------
Repair possible failure to update hint bits back to disk, per
http://archives.postgresql.org/pgsql-hackers/2004-10/msg00464.php.
I plan a more permanent fix in HEAD, but for the back branches it seems
best to just touch the places that actually have a problem.

Tags:
----
REL7_4_STABLE

Modified Files:
--------------
    pgsql/contrib/pgstattuple:
        pgstattuple.c (r1.12 -> r1.12.4.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pgstattuple/pgstattuple.c.diff?r1=1.12&r2=1.12.4.1)
    pgsql/src/backend/access/heap:
        heapam.c (r1.157 -> r1.157.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/heapam.c.diff?r1=1.157&r2=1.157.2.1)
    pgsql/src/backend/utils/adt:
        ri_triggers.c (r1.63 -> r1.63.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ri_triggers.c.diff?r1=1.63&r2=1.63.2.1)