bug#19423: 25.0.50; incompatible change to `make-obsolete' - added 3rd arg should be optional

[Dmitry Gutov]

Drew Adams <drew.adams@oracle.com> writes:

> In Emacs 23 someone unwisely changed it to mandatory, an
> incompatible change that gratuitously breaks code that could
> be used with older Emacs releases.  Pain for no real gain.

You should look at the code sometimes.

The change is very much compatible: `make-obsolete' can still be called
with only two arguments without error.  The third one is only mandatory
in the advertised calling convention.

Even if it wasn't, it would be too late to fix the "problem": it
wouldn't work in 23 and 24 anyway.