bug#31027: 27.0.50; xref, tags-location-ring equivalent

[Juri Linkov]

>>> What about 'M-x previous error'? Or 'C-u - M-x next-error', to mirror
>>> your example.
>>
>> That's useful, but also different in nature and scope to a global
>> ring, which would not use a local variable (`next-error-function') to
>
> Whether next-error-function is going to be local or not, is subject to
> discussion, see https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20489 and
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=30674.

I have a wish to close these overgrown bugreports and redesign this feature
from scratch ;)

>> navigate to other "errors".  An "xref-location-ring" would be simpler.
>
> What's simpler about that? You'd need some new commands to use it as
> well, right?

Is the idea to use a ring of next-error capable buffers?
So that the next-error command in the current buffer
will return a list of all potentially next-error capable buffers
and allow the user to select the required one.