TH crashes if you reify the Name of a dfun

Prelude Language.Haskell.TH Language.Haskell.TH.Syntax> $(fmap show (classInstances ''Eq [ConT ''Int] >>= reify . head) >>= lift)

<interactive>:1:3:
    Exception when trying to run compile-time code:
      <interactive>: panic! (the 'impossible' happened)
  (GHC version 7.0.1 for x86_64-unknown-linux):
	reifyType PredTy
    <pred>base:GHC.Classes.Eq{tc 23} ghc-prim:GHC.Types.Int{(w) tc 3J}

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

      Code: (>>=)
              fmap
                (show)
                ((>>=)
                   classInstances 'Eq [Language.Haskell.TH.Syntax.ConT 'Int]
                   (.) reify head)
              lift
    In the expression:
      $(fmap show (classInstances 'Eq [ConT 'Int] >>= reify . head)
      >>=
        lift)
    In an equation for `it':
        it
          = $(fmap show (classInstances 'Eq [ConT 'Int] >>= reify . head)
            >>=
              lift)

The same thing happens when compiling with ghc rather than using GHCi. Also, it looks like the pretty printer is displaying ''Eq and ''Int incorrectly.

Trac metadata

Trac field	Value
Version	7.0.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Template Haskell
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