pgsql: Fix 8.2 breakage of domains over array types, and add a

Log Message:
-----------
Fix 8.2 breakage of domains over array types, and add a regression test case
to cover it.  Per report from Anton Pikhteryev.

Modified Files:
--------------
    pgsql/src/backend/utils/cache:
        lsyscache.c (r1.149 -> r1.150)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/cache/lsyscache.c.diff?r1=1.149&r2=1.150)
    pgsql/src/test/regress/expected:
        domain.out (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/domain.out.diff?r1=1.39&r2=1.40)
    pgsql/src/test/regress/sql:
        domain.sql (r1.22 -> r1.23)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/domain.sql.diff?r1=1.22&r2=1.23)