bug#61730: 30.0.50; Compiler warnings for delq and delete

[Richard Stallman]

  > I think we should add compiler warnings for `delete' and `delq' function
  > calls whose return values are unused.

I think that is a good idea.  But before we release such a change, we
should try compiling a lot of code with it and study the warnings produced.
Are nearly all the warnings caused by real bugs?

There are some special cases where the unused value is not a bug.  For
instance, when you know that the elements to be deleted cannot include
the first element, it is safe not to store the result back.  One can
argue that it is cleaner to do so anyway, but that's a matter of
neatness, not a bug.

-- 
Dr Richard Stallman (https://stallman.org)
Chief GNUisance of the GNU Project (https://gnu.org)
Founder, Free Software Foundation (https://fsf.org)
Internet Hall-of-Famer (https://internethalloffame.org)