Dump it. Three common sense rules apply here:-
1. Images are valuable.
2. Developer is cheap.
3. Life is short.
To elaborate on (3), best to keep it sweet, and not waste precious life time in the darkroom fidding with old developers and other chemistry. Like so much else is life, fresh is everything!
To give you a more personal perspective on all the above, I recently did a complete re-evaluation of all my darkroom processes, and madethe decision to dump a large selection of developers, notably home mixed Thornton and Leica two bath (some of you may recall that in the past I've been praising the former on this forum as literally the gods' own film nectar), old Microdol and HC-110 I've had bottled for ages and a full carton of old classic Agfa (does anyone remember Rodinal Special?) concentrated developers they ceased manufacturing in the early years of this century if not earlier. For the time being I have returned to the old tried and true D76/ID11. I fully intend to give Xtol a test in the near future, but I must admit I've been somewhat put off this developer by the conflicting advice I've read in this forum.
With respect to the case of Agfa I have five unopened bottles of Rodinal Special left and I confess to having such a nostalgic fondness for this developer, that I intend to run tests on a few older films from my freezer, some I've kept since the '90s. Agfa RodSpec gave me absolutely the best negatives I've ever shot on such films as Kodak Panatomic-X and TMax V.1 as well as the older version of Ilford Pan F.
As I see it, for me recalling the past with rose-tinted lenses is pleasant over a Cuban cigarillo and a glass of good vintage red at the end of the day, but today's photography like today'snlife is really all about the here and now. Like everyone else I have to live in the present, even in the darkroom. Using only fresh developers reduces the potential for disasters by one factor less. I like this thought.