pgsql: Remove fairly useless mixed-case identifier test that causes

Log Message:
-----------
Remove fairly useless mixed-case identifier test that causes locale
dependencies.

Modified Files:
--------------
    pgsql/src/test/regress/expected:
        foreign_data.out (r1.2 -> r1.3)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/foreign_data.out?r1=1.2&r2=1.3)
    pgsql/src/test/regress/sql:
        foreign_data.sql (r1.1 -> r1.2)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/foreign_data.sql?r1=1.1&r2=1.2)