panic! compiling Y combinator with optimizations

The following causes GHC 7.6.3, 7.8.3 and 7.10.1 (at least) to panic when compiling with optimizations:

module Y (y) where

newtype Rec a = Rec { out :: Rec a -> a}

k x = out x x

y f = (f . k) (Rec (f . k))

/tmp ««« ghc -O y.hs -fforce-recomp
[1 of 1] Compiling Y                ( y.hs, y.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.10.1 for x86_64-unknown-linux):
        Simplifier ticks exhausted
  When trying UnfoldingDone a_sof
  To increase the limit, use -fsimpl-tick-factor=N (default 100)
  If you need to do this, let GHC HQ know, and what factor you needed
  To see detailed counts use -ddump-simpl-stats
  Total ticks: 5282

Trac metadata

Trac field	Value
Version	7.10.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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