Added paragraph to user's guide about Nominal role for Set
Added paragraph to user's guide about Nominal role for Set

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