runtimeRepPrimRep panic with a representation-polymorphic newtype

The following program runs into a panic on HEAD:

{-# LANGUAGE DataKinds, DatatypeContexts, MagicHash, UnliftedNewtypes, TypeFamilies #-}

module EtaExpandNewtypeTF where

import Data.Kind
import GHC.Exts

type R :: Type -> RuntimeRep
type family R a where
  R Float  = FloatRep
  R Double = DoubleRep

type F :: forall (a :: Type) -> TYPE (R a)
type family F a where
  F Float  = Float#
  F Double = Double#

type C :: Type -> Constraint
class C a where {}

type N :: forall (a :: Type) -> TYPE (R a)
newtype C a => N a = MkN (F a)

foo1 :: C Float => F Float -> N Float
foo1 = MkN

foo2 :: C Double => () -> F Double -> N Double
foo2 _ = MkN

  GHC version 9.5.20220525:
        runtimeRepPrimRep
  typePrimRep (F Float :: TYPE (R Float))
  R Float
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler\GHC\Utils\Panic.hs:182:37 in ghc:GHC.Utils.Panic
        pprPanic, called at compiler\GHC\Types\RepType.hs:614:5 in ghc:GHC.Types.RepType
        runtimeRepPrimRep, called at compiler\GHC\Types\RepType.hs:582:5 in ghc:GHC.Types.RepType
        kindPrimRep, called at compiler\GHC\Types\RepType.hs:534:18 in ghc:GHC.Types.RepType
        typePrimRep, called at compiler\GHC\Types\RepType.hs:181:22 in ghc:GHC.Types.RepType
        isZeroBitTy, called at compiler\GHC\Core\Unfold.hs:617:43 in ghc:GHC.Core.Unfold

We also get an error with Core Lint:

*** Core Lint errors : in result of Desugar (after optimization) ***
EtaExpandNewtypeTF.hs:25:1: warning:
    Binder does not have a fixed runtime representation: ds_dHN :: (F Float :: TYPE
                                                                                 (R Float))
    In the RHS of foo1 :: C Float =>
                          (F Float |> (TYPE (D:R:R[0]))_N)
                          -> (N Float |> (TYPE (D:R:R[0]))_N)
    In the body of lambda with binder $dC_aH8 :: C Float
    In the body of lambda with binder ds_dHN :: F Float
    Substitution: [TCvSubst
                     In scope: InScope {}
                     Type env: []
                     Co env: []]

This seems to be a different issue than #21544 (closed), as changing newtype constructors to always inline fixes that bug but doesn't fix this one.