pgsql: As long as we're forcing an ORDER BY in these four join queries,

Log Message:
-----------
As long as we're forcing an ORDER BY in these four join queries, we had
better make sure the sort order is totally specified; else we get burnt
by platform-specific behavior of qsort() with equal keys.  Per buildfarm
results.

Modified Files:
--------------
    pgsql/src/test/regress/expected:
        join.out (r1.21 -> r1.22)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/join.out.diff?r1=1.21&r2=1.22)
    pgsql/src/test/regress/sql:
        join.sql (r1.14 -> r1.15)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/join.sql.diff?r1=1.14&r2=1.15)