configure: don't use ms style packing

It is not used in libdvdread and we should use the same structure packing as libdvdread.

There are still issues using packed structures but it avoids some crashes with LLVM builds. see libdvdread!41 (merged)

Not using packed structures in libdvdread and libdvdnav is the proper fix. But this is probably an easier patch to merge.

mentioned in merge request vlc!2400 (merged)

changed the description

mentioned in merge request libdvdread!41 (merged)

This patch is not need anymore if/when libdvdread!42 is merged. Although it's still the right thing to do to avoid mismatches between compiler setup of libdvdread and libdvdnav.

mentioned in merge request libdvdread!42

Duplicate of !29

closed