Fix the boot dfun impedence-matching binding
Fix the boot dfun impedence-matching binding

In TcRnDriver.checkHiBootIface' we were generating an
impedence-matching binding
   $fxToRecMaybe = $fToRecMaybe
but the type of the former was gotten from the *hi-boot*
file, so its type constructor was not fully fleshed out.
That should never happen.

Fix is easy, happily.  A dark corner.

oldmanmike/ghc,tjakway/ghcjvm,snoyberg/ghc,sdiehl/ghc,anton-dessiatov/ghc,oldmanmike/ghc,ml9951/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,fmthoma/ghc,anton-dessiatov/ghc,AlexanderPankiv/ghc,da-x/ghc,gridaphobe/ghc,da-x/ghc,wxwxwwxxx/ghc,shlevy/ghc,siddhanathan/ghc,siddhanathan/ghc,tjakway/ghcjvm,TomMD/ghc,mcschroeder/ghc,sgillespie/ghc,mfine/ghc,snoyberg/ghc,nushio3/ghc,snoyberg/ghc,sgillespie/ghc,gridaphobe/ghc,ml9951/ghc,nushio3/ghc,siddhanathan/ghc,ezyang/ghc,oldmanmike/ghc,urbanslug/ghc,anton-dessiatov/ghc,TomMD/ghc,ezyang/ghc,mfine/ghc,elieux/ghc,vikraman/ghc,mettekou/ghc,oldmanmike/ghc,gridaphobe/ghc,shlevy/ghc,GaloisInc/halvm-ghc,tjakway/ghcjvm,vTurbine/ghc,olsner/ghc,mettekou/ghc,olsner/ghc,ezyang/ghc,fmthoma/ghc,AlexanderPankiv/ghc,mfine/ghc,sgillespie/ghc,olsner/ghc,christiaanb/ghc,da-x/ghc,wxwxwwxxx/ghc,nkaretnikov/ghc,shlevy/ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,fmthoma/ghc,nkaretnikov/ghc,snoyberg/ghc,vikraman/ghc,urbanslug/ghc,acowley/ghc,mcschroeder/ghc,nushio3/ghc,vTurbine/ghc,TomMD/ghc,acowley/ghc,gridaphobe/ghc,vTurbine/ghc,AlexanderPankiv/ghc,siddhanathan/ghc,vikraman/ghc,da-x/ghc,da-x/ghc,anton-dessiatov/ghc,shlevy/ghc,mfine/ghc,ghc-android/ghc,da-x/ghc,nkaretnikov/ghc,fmthoma/ghc,wxwxwwxxx/ghc,elieux/ghc,sgillespie/ghc,mcschroeder/ghc,tjakway/ghcjvm,urbanslug/ghc,mfine/ghc,anton-dessiatov/ghc,christiaanb/ghc,tjakway/ghcjvm,ezyang/ghc,ml9951/ghc,vTurbine/ghc,mettekou/ghc,sdiehl/ghc,snoyberg/ghc,ezyang/ghc,ghc-android/ghc,ghc-android/ghc,mettekou/ghc,sgillespie/ghc,gridaphobe/ghc,elieux/ghc,olsner/ghc,sdiehl/ghc,TomMD/ghc,ml9951/ghc,ml9951/ghc,nkaretnikov/ghc,ml9951/ghc,mettekou/ghc,ghc-android/ghc,ml9951/ghc,mfine/ghc,acowley/ghc,nkaretnikov/ghc,wxwxwwxxx/ghc,christiaanb/ghc,da-x/ghc,vikraman/ghc,wxwxwwxxx/ghc,acowley/ghc,AlexanderPankiv/ghc,anton-dessiatov/ghc,oldmanmike/ghc,GaloisInc/halvm-ghc,urbanslug/ghc,fmthoma/ghc,oldmanmike/ghc,shlevy/ghc,sdiehl/ghc,ghc-android/ghc,mettekou/ghc,mcschroeder/ghc,ezyang/ghc,anton-dessiatov/ghc,christiaanb/ghc,AlexanderPankiv/ghc,christiaanb/ghc,siddhanathan/ghc,vikraman/ghc,olsner/ghc,elieux/ghc,ml9951/ghc,elieux/ghc,acowley/ghc,nkaretnikov/ghc,GaloisInc/halvm-ghc,TomMD/ghc,ezyang/ghc,urbanslug/ghc,fmthoma/ghc,nushio3/ghc,mfine/ghc,vTurbine/ghc,siddhanathan/ghc,urbanslug/ghc,acowley/ghc,sdiehl/ghc,TomMD/ghc,urbanslug/ghc,snoyberg/ghc,wxwxwwxxx/ghc,christiaanb/ghc,gridaphobe/ghc,AlexanderPankiv/ghc,fmthoma/ghc,gridaphobe/ghc,olsner/ghc,shlevy/ghc,nushio3/ghc,TomMD/ghc,nushio3/ghc,christiaanb/ghc,acowley/ghc,ghc-android/ghc,sdiehl/ghc,GaloisInc/halvm-ghc,oldmanmike/ghc,mettekou/ghc,mcschroeder/ghc,wxwxwwxxx/ghc,vTurbine/ghc,sgillespie/ghc,olsner/ghc,shlevy/ghc,tjakway/ghcjvm,snoyberg/ghc,nushio3/ghc,sgillespie/ghc,elieux/ghc,ghc-android/ghc,vTurbine/ghc,elieux/ghc,siddhanathan/ghc,nkaretnikov/ghc,vikraman/ghc,mcschroeder/ghc,GaloisInc/halvm-ghc,vikraman/ghc,mcschroeder/ghc,sdiehl/ghc