The patch below does two things:

(i) fixes a small bug in the new partition code
This is the final chunk s/n/slot/. I'll refrain from giving a vi script.
This is uncontroversial.

(ii) removes ancient garbage concerning disk managers
This may well be controversial.

(Long ago, when disks became larger than 500 MB, lots of tricks were
invented to keep DOS happy. Both hardware tricks and software tricks.
One of the software tricks was the invention of boot managers.
There have been many of those. The Linux kernel has had support
for two of them: OnTrack Disk Manager and EZdrive.
More precisely: there have been many versions of both OnTrack Disk Manager
and EZdrive, and the kernel had support for a few of these versions.

I think the time has come to remove the automatic support - every now
and then it bites some innocent user, and the support is not really
needed any longer, and the support is for outdated versions of these
boot managers.

No doubt it will turn out that users still exist that use some form
of this stuff, but I would prefer to support them by explicit
kernel boot parameters, rather than by code that guesses what
might be the right thing to do.

The patch below just rips out the old stuff. Depending on the screams
this might provoke I expect to add some boot parameters.)