GHC can't constant fold even basic power (^) applications for Int (and others?)

[nix-shell:/tmp]$ ghc -O2 -fforce-recomp -ddump-simpl S.hs 2>&1 | tail
[GblId,
 Unf=Unf{Src=<vanilla>, TopLvl=True, Value=False, ConLike=False,
         WorkFree=False, Expandable=False, Guidance=IF_ARGS [] 50 20}]
foo
  = case GHC.Real.$wf1 2# 1# of ww2_a2zt { __DEFAULT ->
    GHC.Types.I# ww2_a2zt
    }

[nix-shell:/tmp]$ cat S.hs
module S (foo) where
foo :: Int
foo = (2 :: Int) ^ (1 :: Int)

This seems like a fairly strange thing to not optimise when constants are known on both sides. I'm complaining about Int for this particular ticket.