CURRENT: supeblock hash failure - CURRENT wrecking disks

Hello,

today I ran into a ctastrophy with r350671. After installing a fresh compiled
system and rebooted the box, UEFI loader dropped a bunch of errors, like some
hex numbers stating, that a hash/superblock has is wrong and then the booting
stopped at the OK loader prompt.

Rebooting the machine with the FreeBSD-13-CURRENT image from 1st August 2019
and trying to fsck the filesystem(s) on the boot SSD (UFS2, journaling and trim
on), lots of unresolved block errors occured. But that didn't help much.
Further, after several checks, I saw some commits to the ffs code recently adn
tried to restore a copy of the superblock of each filesystem (in contrary to
the man page for fsck_ufs, the first backup superblock resides in 192, not
160!). But things then get even worse, it seems the whole /boot structure is
corrupted, the loader can not find the recent kernel and kernel.old is crashing.

What's wrong here :-(

regards,
oh