bug#38912: 27.0.60; PDumper meets segmentation fault when evil is loaded

[Stefan Monnier]

>> I actually *expected* that `equal` on window configs would behave like
>> `eq`.  It would have never occurred to me (before I looked at the code)
>> that it could be different (although in retrospect, I can see reasons
>> why it could make sense).
> Since we have a dedicated comparison function there, why is it
> important what eq and equal do with these objects?

The immediate reason why it's relevant is that it affects what `sxhash`
needs to do.  The existence of `compare-window-configurations` is not
directly relevant to the question (tho it arguably makes it less
important for `equal` to behave structurally since it provides an
alternative for those callers who would need it).


        Stefan