GHC HEAD panics trying to splice a type

This:

{-# LANGUAGE TemplateHaskell #-}

module Test where

import Language.Haskell.TH
import Foreign

sizeq :: Name -> Q Exp
sizeq n = [| sizeOf (undefined :: $(conT n)) |]

leads to

ghc.EXE: panic! (the 'impossible' happened)
  (GHC version 6.11.20090823 for i386-unknown-mingw32):
	kcSpliceType

Trac metadata

Trac field	Value
Version	6.11
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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