Fix bug in Ada packed array handling

Fix bug in Ada packed array handling

A user found a bug where an array of packed arrays was printed
incorrectly.  The bug here is that the packed array has a bit stride,
but the outer array does not -- and should not.  However,
update_static_array_size does not distinguish between an array of
packed arrays and a multi-dimensional packed array, and for the
latter, only the innermost array will end up with a stride.

This patch fixes the problem by adding a flag to indicate whether a
given array type is a constituent of a multi-dimensional array.