Fix Trac #2597 (first bug): correct type checking for empty list
Fix Trac #2597 (first bug): correct type checking for empty list

The GHC front end never generates (ExplicitList []), but TH can.
This patch makes the typechecker robust to such programs.


TomMD/ghc,AlexanderPankiv/ghc,holzensp/ghc,ml9951/ghc,ml9951/ghc,tibbe/ghc,sgillespie/ghc,gridaphobe/ghc,nkaretnikov/ghc,elieux/ghc,nushio3/ghc,fmthoma/ghc,hferreiro/replay,nkaretnikov/ghc,sgillespie/ghc,vikraman/ghc,TomMD/ghc,forked-upstream-packages-for-ghcjs/ghc,sgillespie/ghc,nomeata/ghc,ghc-android/ghc,TomMD/ghc,ilyasergey/GHC-XAppFix,acowley/ghc,vTurbine/ghc,christiaanb/ghc,mfine/ghc,ghc-android/ghc,siddhanathan/ghc,mettekou/ghc,mfine/ghc,wxwxwwxxx/ghc,nkaretnikov/ghc,mcmaniac/ghc,frantisekfarka/ghc-dsi,acowley/ghc,mfine/ghc,sgillespie/ghc,sdiehl/ghc,shlevy/ghc,forked-upstream-packages-for-ghcjs/ghc,shlevy/ghc,christiaanb/ghc,nushio3/ghc,lukexi/ghc-7.8-arm64,snoyberg/ghc,snoyberg/ghc,forked-upstream-packages-for-ghcjs/ghc,tibbe/ghc,vikraman/ghc,forked-upstream-packages-for-ghcjs/ghc,lukexi/ghc-7.8-arm64,tjakway/ghcjvm,gridaphobe/ghc,nushio3/ghc,ml9951/ghc,nomeata/ghc,mcschroeder/ghc,mcschroeder/ghc,mfine/ghc,ekmett/ghc,jstolarek/ghc,mcschroeder/ghc,christiaanb/ghc,nomeata/ghc,shlevy/ghc,tjakway/ghcjvm,mettekou/ghc,ezyang/ghc,sdiehl/ghc,anton-dessiatov/ghc,forked-upstream-packages-for-ghcjs/ghc,olsner/ghc,fmthoma/ghc,oldmanmike/ghc,hferreiro/replay,tjakway/ghcjvm,sdiehl/ghc,TomMD/ghc,bitemyapp/ghc,christiaanb/ghc,nathyong/microghc-ghc,shlevy/ghc,oldmanmike/ghc,jstolarek/ghc,sdiehl/ghc,siddhanathan/ghc,lukexi/ghc-7.8-arm64,da-x/ghc,green-haskell/ghc,ryantm/ghc,siddhanathan/ghc,vikraman/ghc,frantisekfarka/ghc-dsi,AlexanderPankiv/ghc,vTurbine/ghc,sdiehl/ghc,sdiehl/ghc,gcampax/ghc,olsner/ghc,sdiehl/ghc,hferreiro/replay,spacekitteh/smcghc,sgillespie/ghc,nathyong/microghc-ghc,nkaretnikov/ghc,nathyong/microghc-ghc,mfine/ghc,ml9951/ghc,mcschroeder/ghc,urbanslug/ghc,ezyang/ghc,anton-dessiatov/ghc,green-haskell/ghc,vikraman/ghc,anton-dessiatov/ghc,mettekou/ghc,vTurbine/ghc,ezyang/ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,lukexi/ghc,fmthoma/ghc,siddhanathan/ghc,AlexanderPankiv/ghc,green-haskell/ghc,olsner/ghc,TomMD/ghc,tibbe/ghc,lukexi/ghc,acowley/ghc,urbanslug/ghc,spacekitteh/smcghc,nomeata/ghc,nushio3/ghc,christiaanb/ghc,nushio3/ghc,gcampax/ghc,anton-dessiatov/ghc,mettekou/ghc,anton-dessiatov/ghc,mcschroeder/ghc,green-haskell/ghc,holzensp/ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,nathyong/microghc-ghc,vTurbine/ghc,nkaretnikov/ghc,da-x/ghc,GaloisInc/halvm-ghc,bitemyapp/ghc,spacekitteh/smcghc,tjakway/ghcjvm,GaloisInc/halvm-ghc,ezyang/ghc,olsner/ghc,frantisekfarka/ghc-dsi,lukexi/ghc-7.8-arm64,oldmanmike/ghc,mcmaniac/ghc,spacekitteh/smcghc,GaloisInc/halvm-ghc,fmthoma/ghc,lukexi/ghc-7.8-arm64,olsner/ghc,oldmanmike/ghc,tibbe/ghc,nkaretnikov/ghc,urbanslug/ghc,GaloisInc/halvm-ghc,elieux/ghc,GaloisInc/halvm-ghc,tjakway/ghcjvm,ml9951/ghc,anton-dessiatov/ghc,ryantm/ghc,jstolarek/ghc,forked-upstream-packages-for-ghcjs/ghc,gcampax/ghc,vTurbine/ghc,lukexi/ghc,gridaphobe/ghc,snoyberg/ghc,siddhanathan/ghc,mettekou/ghc,ghc-android/ghc,wxwxwwxxx/ghc,ilyasergey/GHC-XAppFix,lukexi/ghc,jstolarek/ghc,vikraman/ghc,AlexanderPankiv/ghc,gcampax/ghc,TomMD/ghc,shlevy/ghc,elieux/ghc,snoyberg/ghc,green-haskell/ghc,vTurbine/ghc,gridaphobe/ghc,gcampax/ghc,hferreiro/replay,tjakway/ghcjvm,ezyang/ghc,nushio3/ghc,acowley/ghc,ml9951/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,ekmett/ghc,urbanslug/ghc,sgillespie/ghc,oldmanmike/ghc,elieux/ghc,sgillespie/ghc,ryantm/ghc,shlevy/ghc,snoyberg/ghc,holzensp/ghc,snoyberg/ghc,urbanslug/ghc,mettekou/ghc,frantisekfarka/ghc-dsi,spacekitteh/smcghc,ezyang/ghc,oldmanmike/ghc,wxwxwwxxx/ghc,tibbe/ghc,mcmaniac/ghc,gridaphobe/ghc,ml9951/ghc,bitemyapp/ghc,snoyberg/ghc,wxwxwwxxx/ghc,forked-upstream-packages-for-ghcjs/ghc,nathyong/microghc-ghc,hferreiro/replay,urbanslug/ghc,gcampax/ghc,mcschroeder/ghc,holzensp/ghc,ezyang/ghc,jstolarek/ghc,siddhanathan/ghc,ekmett/ghc,ghc-android/ghc,vikraman/ghc,fmthoma/ghc,acowley/ghc,ghc-android/ghc,elieux/ghc,da-x/ghc,elieux/ghc,mfine/ghc,holzensp/ghc,oldmanmike/ghc,gridaphobe/ghc,ilyasergey/GHC-XAppFix,anton-dessiatov/ghc,gcampax/ghc,gridaphobe/ghc,bitemyapp/ghc,mcmaniac/ghc,ryantm/ghc,AlexanderPankiv/ghc,christiaanb/ghc,siddhanathan/ghc,da-x/ghc,vTurbine/ghc,TomMD/ghc,hferreiro/replay,mettekou/ghc,mfine/ghc,AlexanderPankiv/ghc,ghc-android/ghc,elieux/ghc,acowley/ghc,da-x/ghc,da-x/ghc,wxwxwwxxx/ghc,ekmett/ghc,nkaretnikov/ghc,olsner/ghc,urbanslug/ghc,ilyasergey/GHC-XAppFix,vikraman/ghc,da-x/ghc,mcschroeder/ghc,christiaanb/ghc,olsner/ghc,nomeata/ghc,acowley/ghc,bitemyapp/ghc,fmthoma/ghc,wxwxwwxxx/ghc,ghc-android/ghc,ekmett/ghc,shlevy/ghc,wxwxwwxxx/ghc,hferreiro/replay,fmthoma/ghc,ryantm/ghc,mcmaniac/ghc,frantisekfarka/ghc-dsi,lukexi/ghc,ml9951/ghc,nushio3/ghc