pgsql: Alter regression test cases that rely on the sort order of "aa".

Log Message:
-----------
Alter regression test cases that rely on the sort order of "aa".  Some
locales (da_DK, fo_FO, kl_GL, nb_NO, nn_NO in glibc) sort "aa" after "z".

Modified Files:
--------------
    pgsql/src/test/regress/sql:
        alter_table.sql (r1.59 -> r1.60)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/alter_table.sql?r1=1.59&r2=1.60)
        join.sql (r1.25 -> r1.26)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/join.sql?r1=1.25&r2=1.26)
        select_implicit.sql (r1.6 -> r1.7)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/select_implicit.sql?r1=1.6&r2=1.7)
    pgsql/src/test/regress/expected:
        alter_table.out (r1.111 -> r1.112)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/alter_table.out?r1=1.111&r2=1.112)
        join.out (r1.34 -> r1.35)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/join.out?r1=1.34&r2=1.35)
        select_implicit.out (r1.17 -> r1.18)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/select_implicit.out?r1=1.17&r2=1.18)
        select_implicit_1.out (r1.9 -> r1.10)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/select_implicit_1.out?r1=1.9&r2=1.10)
        select_implicit_2.out (r1.6 -> r1.7)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/select_implicit_2.out?r1=1.6&r2=1.7)