Levity polymorphic arguments are thought to be too strict

I don't expect the error call to be evaluated in this program.

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE MagicHash #-}
module Main where

import GHC.Exts
import GHC.Int

{-# NOINLINE foo #-}
foo = error "abc"

main = print (I# (reallyUnsafePtrEquality# foo foo))

If we compile and run with optimisations then it produces an error.

[nix-shell:~/ghc-multi-hmi]$ _build/stage1/bin/ghc BoxedRep.hs -O2
[1 of 2] Compiling Main             ( BoxedRep.hs, BoxedRep.o ) [Optimisation flags changed]
[2 of 2] Linking BoxedRep [Objects changed]

[nix-shell:~/ghc-multi-hmi]$ ./BoxedRep 
BoxedRep: abc
CallStack (from HasCallStack):
  error, called at BoxedRep.hs:9:8 in main:Main

@sheaf Already has a more thorough diagnosis but the crux of the matter is in mkArgInfo.add_type_strictness incorrectly determines that the arguments have strict demand due to isLiftedType_maybe returning the wrong thing for BoxedRep l (see #20837 (closed))