Fix warnings in deSugar/DsGRHSs.lhs
Fix warnings in deSugar/DsGRHSs.lhs

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