Adapt gdb.ada/pkd_arr_elem.exp to accept reordered components

Adapt gdb.ada/pkd_arr_elem.exp to accept reordered components

Recent versions of GNAT are capable of reordering record components
to make their access for efficient. This patch adapts this test to
accept both cases (reordered or not).

gdb/testsuite/ChangeLog:

        * gdb.ada/pkd_arr_elem.exp: Adapt "print test" test to accept
        output with components being reordered.