Add ListSetOps.removeRedundant
Add ListSetOps.removeRedundant

It's needed in ghc/InteractiveUI, although not in the compiler itself

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