bug#49734: [External] : bug#49734: 28.0.50; define-obsolete-variable-alias

[Drew Adams]

> This change breaks existing libraries.
> Better to deprecate old forms for a few years
> rather than gratuitously and prematurely sow chaos.
> 
> P.S.  Please undo this incompatible change:
> 
> -(defun make-obsolete-variable (obsolete-name current-name &optional when
> access-type)
> +(defun make-obsolete-variable ( obsolete-name current-name when
> +                                &optional access-type)

+1.

In general, moving an optional arg to mandatory
makes things harder for code that tries to support
multiple releases.  And it doesn't gain Emacs much,
other than perhaps a byte-compiler warning for more
recent code that omits the now-mandatory arg.

Does this arg really need to _be_ mandatory now, or
is this just another turn of the screw to provide
additional warning support by the compiler?