coredump: raise the coredump save size on 64bit systems to 32G (and lower it to 1G...

coredump: raise the coredump save size on 64bit systems to 32G (and lower it to 1G on 32bit systems)

Apparently 2G is too low for various real-life systems. But raising it
universally above 2^32 sounds wrong to me, since that makes no sense on
32bit systems, that we still support.

Hence, let's raise the limit to 32G on 64bit systems, and *lower* it to
1G on 32bit systems.

32G is 4 orders of magnitude higher then the old settings. Let's hope
that's enough for now. Should this not be enough we can raise it
further.

Fixes: #22076