Remove some unused build system variables
Remove some unused build system variables

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