8.0 rc1 panics in applyTypeToArgs

To reproduce, clone https://github.com/rrnewton/haskell-lockfree and switch to ghc-8.0 branch. Then run cabal install atomic-primops/ (note the trailing slash, we don't want to install it from Hackage). It should fail with a message like this:

➜  haskell-lockfree git:(ghc-8.0) ✗ cabal install atomic-primops/
Warning: The package list for 'hackage.haskell.org' is 25.1 days old.
Run 'cabal update' to get the latest list of available packages.
Resolving dependencies...
Notice: installing into a sandbox located at
/home/omer/haskell/haskell-lockfree/.cabal-sandbox
Configuring primitive-0.6.1.0...
Building primitive-0.6.1.0...
Warning: /tmp/pkgConf-primitive-0.6.110252023621350490027.0: Unrecognized
field abi on line 21
Installed primitive-0.6.1.0
Configuring atomic-primops-0.8.0.2...
Building atomic-primops-0.8.0.2...
Failed to install atomic-primops-0.8.0.2
Build log ( /home/omer/haskell/haskell-lockfree/.cabal-sandbox/logs/atomic-primops-0.8.0.2.log ):
[1 of 1] Compiling Main             ( atomic-primops/dist/dist-sandbox-ad71ba7e/setup/setup.hs, atomic-primops/dist/dist-sandbox-ad71ba7e/setup/Main.o )
Linking atomic-primops/dist/dist-sandbox-ad71ba7e/setup/setup ...
Configuring atomic-primops-0.8.0.2...
Building atomic-primops-0.8.0.2...
Preprocessing library atomic-primops-0.8.0.2...
[1 of 3] Compiling Data.Atomics.Internal ( Data/Atomics/Internal.hs, dist/dist-sandbox-ad71ba7e/build/Data/Atomics/Internal.o )

Data/Atomics/Internal.hs:69:20: warning:
    Defined but not used: data constructor ‘Ticket’
[2 of 3] Compiling Data.Atomics.Counter ( Data/Atomics/Counter.hs, dist/dist-sandbox-ad71ba7e/build/Data/Atomics/Counter.o )
[3 of 3] Compiling Data.Atomics     ( Data/Atomics.hs, dist/dist-sandbox-ad71ba7e/build/Data/Atomics.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 8.0.0.20160111 for x86_64-unknown-linux):
        applyTypeToArgs
  Expression: readMutVar# eta_s4sC st_s4sD
  Type: forall d_15 a_12.
        MutVar# d_15 a_12 -> State# d_15 -> (# State# d_15, a_12 #)
  Args: [eta_s4sC, st_s4sD]

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

cabal: Error: some packages failed to install:
atomic-primops-0.8.0.2 failed during the building phase. The exception was:
ExitFailure 1

Trac metadata

Trac field	Value
Version	8.0.1-rc1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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