bug#62720: 29.0.60; Not easy at all to upgrade :core packages like Eglot

[Stefan Monnier]

>> Why did the original code use symbol-name, but the new one doesn't?
> To my knowledge, completing-read given a collection of symbols will use
> the symbol names as candidates, or is this more complicated?

It mostly works.  Strictly speaking a completion table can be either:
- a list of strings
- an alist whose keys are either strings or symbols
and the code handles those two cases together so a list of symbols tend
to work just as well, but if your first symbol happens to be `lambda` or
`closure`, you're out of luck.


        Stefan