Panic when loading file with nested pattern synonyms into ghci

The following code compiles fine for me in GHC 7.10.1, but fails in GHC 8.1.20160502

{-# LANGUAGE PatternSynonyms #-}
{-# LANGUAGE ViewPatterns #-}

data Foo a = Foo a a

pattern A a1 a2 = Foo a1 a2
pattern B a1 a2 = A a1 a2

The problem is the nested pattern. Compiling gives:

[1 of 1] Compiling Main             ( Bug1.hs, interpreted )
ghc-stage2: panic! (the 'impossible' happened)
  (GHC version 8.1.20160502 for x86_64-unknown-linux):
        kindPrimRep.go rep_a85f

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

Trac metadata

Trac field	Value
Version	7.10.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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