configure: Add --enable-sanitize-undefined.

Now that we are -fsanitize=undefined clean make sure we keep it that way.

We do have to disable alignment checking. Because we might explicitly
use unaligned accesses (see ALLOW_UNALIGNED).

Rename DISTCHECK_CONFIGURE_FLAGS to AM_DISTCHECK_CONFIGURE_FLAGS, so the
user can override. And add --enable-sanitize-undefined.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
3 files changed