* ada-lang.c (decode_packed_array): Minor change to comment.

* ada-lang.c (decode_packed_array): Minor change to comment.
(ada_value_slice_ptr): New function.
(ada_value_slice): New function.
(ada_evaluate_subexp): Remove XVS-suffix code from subscripting
test.  Don't know why it is there.
Change slice code to use ada_value_slice_ptr and ada_value_slice, and
to avoid dereferencing huge arrays from which one is slicing.
(empty_array): Correct to return an array rather than
a subrange value.
* ada-valprint.c (print_optional_low_bound): Don't print lower bound
on empty arrays (let'em use 'FIRST instead).