pgsql: Provide regression testing for plperlu, and for plperl+plperlu

Log Message:
-----------
Provide regression testing for plperlu, and for plperl+plperlu interaction.
The latter are only run if the platform can run both interpreters in the
same backend.

Modified Files:
--------------
    pgsql/src/pl/plperl:
        GNUmakefile (r1.39 -> r1.40)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/GNUmakefile?r1=1.39&r2=1.40)
    pgsql/src/tools/msvc:
        vcregress.pl (r1.12 -> r1.13)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/tools/msvc/vcregress.pl?r1=1.12&r2=1.13)

Added Files:
-----------
    pgsql/src/pl/plperl/expected:
        plperl_plperlu.out (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/expected/plperl_plperlu.out?rev=1.1&content-type=text/x-cvsweb-markup)
        plperlu.out (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/expected/plperlu.out?rev=1.1&content-type=text/x-cvsweb-markup)
    pgsql/src/pl/plperl/sql:
        plperl_plperlu.sql (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/sql/plperl_plperlu.sql?rev=1.1&content-type=text/x-cvsweb-markup)
        plperlu.sql (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/sql/plperlu.sql?rev=1.1&content-type=text/x-cvsweb-markup)