pgsql: Insert ORDER BY into a few regression test queries that now have

Log Message:
-----------
Insert ORDER BY into a few regression test queries that now have unstable
results due to syncscan patch, when shared_buffers is small enough. Per
buildfarm reports and some local testing with shared_buffers set to the
lowest value considered by initdb.

Modified Files:
--------------
pgsql/src/test/regress/expected:
portals.out (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/portals.out.diff?r1=1.12&r2=1.13)
prepare.out (r1.13 -> r1.14)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/prepare.out.diff?r1=1.13&r2=1.14)
transactions.out (r1.16 -> r1.17)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/transactions.out.diff?r1=1.16&r2=1.17)
pgsql/src/test/regress/sql:
portals.sql (r1.9 -> r1.10)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/portals.sql.diff?r1=1.9&r2=1.10)
prepare.sql (r1.5 -> r1.6)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/prepare.sql.diff?r1=1.5&r2=1.6)
transactions.sql (r1.13 -> r1.14)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/transactions.sql.diff?r1=1.13&r2=1.14)