No TypeRep for unboxed tuples

This now crashes on GHC HEAD:

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

import Data.Typeable
import GHC.Exts

main :: IO ()
main = print $ typeOf (Proxy :: Proxy (# Int, Int #))

$ /opt/ghc/head/bin/ghc -O2 -fforce-recomp Example.hs
[1 of 1] Compiling Main             ( Example.hs, Example.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 8.1.20160317 for x86_64-unknown-linux):
        tyConRep (#,#)

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

(Previously, this was rejected with an error message, since you couldn't put an unlifted type as the argument of Proxy.)

(Copied from ticket:11471#comment:117929.)

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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