Template bug 2

Windows XP

D:\Tools\ghc>ghc-6.2.1\bin\ghc.exe -fglasgow-exts --make foo.hs
Chasing modules from: foo.hs
Compiling Any              ( ./Any.hs, ./Any.o )
Compiling Foo              ( foo.hs, foo.o )
Loading package base ... linking ... done.
Loading package haskell98 ... linking ... done.
Loading package haskell-src ... linking ... done.
ghc.exe: panic! (the `impossible' happened, GHC version 6.2.1):
        Malformed predicate


module Any where

import Language.Haskell.THSyntax

genAny :: DecQ -> Q [Dec]
genAny decl =
    do{
        d <- decl
      ; case d of
            ClassD _ name _ decls -> sequenceQ [genAnyClass (name) decls]
            _ -> error "genAny can be applied to classes only"
    }

genAnyClass :: String -> [Dec] -> DecQ
genAnyClass name decls =
    do{
        returnQ (DataD [forall] anyName [] [constructor] [])
    }
    where
        anyName = "Any" ++ name ++ "1111"
        constructor = NormalC anyName [(NotStrict, VarT "a")]
        forall = ForallT [] [] (VarT "a")


module Foo where

import Any

class MyInterface a where
        foo :: a -> Int
        foo1 :: Int -> a -> Int

$(genAny (reifyDecl MyInterface))