GHC 9.4 regression: solveWanteds: too many iterations

(Originally spun out of a discussion at https://github.com/well-typed/generics-sop/issues/158.)

GHC 9.2 and earlier accept the following program:

{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE UndecidableSuperClasses #-}
module Bug where

import Data.Kind (Constraint, Type)

data D a

f :: Generic (D a) => ()
f = ()

type family
  AllF (c :: k -> Constraint) (xs :: [k]) :: Constraint where
  AllF _c '[]       = ()
  AllF  c (x ': xs) = (c x, All c xs)

class (AllF c xs, SListI xs) => All (c :: k -> Constraint) (xs :: [k]) where

type SListI = All Top

class Top x
instance Top x

class All SListI (Code a) => Generic a where
  type Code a :: [[Type]]

GHC 9.4.3, however, rejects it with the following error message:

$ ghc-9.4.3 Bug.hs
[1 of 1] Compiling Bug              ( Bug.hs, Bug.o )

Bug.hs:20:6: error:
    * solveWanteds: too many iterations (limit = 4)
        Unsolved: WC {wc_simple =
                        [W] irred_aEQ {0}:: AllF SListI (Code (D a0)) (CIrredCan(irred))
                        [W] irred_aEW {0}:: AllF Top (Code (D a0)) (CIrredCan(irred))
                        [W] $dGeneric_aEH {0}:: Generic (D a0) (CDictCan)
                        [W] $dAll_aEP {0}:: All SListI (Code (D a0)) (CDictCan)
                        [W] $dAll_aEX {0}:: All Top (Code (D a0)) (CDictCan(psc))}
        Simples: {[W] irred_aEQ {0}:: AllF
                                        SListI (Code (D a0)) (CIrredCan(irred)),
                  [W] irred_aEW {0}:: AllF Top (Code (D a0)) (CIrredCan(irred)),
                  [W] $dGeneric_aEH {0}:: Generic (D a0) (CDictCan),
                  [W] $dAll_aEP {0}:: All SListI (Code (D a0)) (CDictCan),
                  [W] $dAll_aEX {0}:: All Top (Code (D a0)) (CDictCan(psc))}
    * In the type signature: f :: Generic (D a) => ()
    Suggested fix:
      Set limit with -fconstraint-solver-iterations=n; n=0 for no limit
   |
20 | f :: Generic (D a) => ()
   |      ^^^^^^^^^^^^^^^^^^^

I've tried increasing the value of -fconstraint-solver-iterations up to 1000, but the error message persists.