pgsql: fix founded hole in recovery after crash, add

Log Message:
-----------
fix founded hole in recovery after crash, add vacuum_delay_point()

Modified Files:
--------------
    pgsql/src/backend/access/gist:
        gist.c (r1.120 -> r1.121)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gist.c.diff?r1=1.120&r2=1.121)
        gistvacuum.c (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gistvacuum.c.diff?r1=1.1&r2=1.2)
        gistxlog.c (r1.2 -> r1.3)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gistxlog.c.diff?r1=1.2&r2=1.3)
    pgsql/src/include/access:
        gist_private.h (r1.4 -> r1.5)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/gist_private.h.diff?r1=1.4&r2=1.5)