bug#40671: [DOC] modify literal objects

[Drew Adams]

> the reason one shouldn't modify byte-code objects
> is ... because doing so can make Emacs crash.

Really?  If something can make Emacs crash it means
there's a bug; that's all.  If there's a bug we
shouldn't document the bugged behavior (it should
be fixed), and we especially shouldn't, in the doc,
say "you should [not] do XYZ" because it can make
Emacs crash.