pgsql: Added another test

Log Message:
-----------
Added another test

Modified Files:
--------------
    pgsql/src/interfaces/ecpg/test/compat_informix:
        Makefile (r1.3 -> r1.4)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/compat_informix/Makefile.diff?r1=1.3&r2=1.4)

Added Files:
-----------
    pgsql/src/interfaces/ecpg/test/compat_informix:
        rnull.pgc (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/compat_informix/rnull.pgc?rev=1.1&content-type=text/x-cvsweb-markup)
    pgsql/src/interfaces/ecpg/test/expected:
        compat_informix-rnull.c (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-rnull.c?rev=1.1&content-type=text/x-cvsweb-markup)
        compat_informix-rnull.stderr (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-rnull.stderr?rev=1.1&content-type=text/x-cvsweb-markup)
        compat_informix-rnull.stdout (r1.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/test/expected/compat_informix-rnull.stdout?rev=1.1&content-type=text/x-cvsweb-markup)