Define CPP in distrib/Makefile-bin-vars.in; fixes #1855 Patch from Christian Maeder
Define CPP in distrib/Makefile-bin-vars.in; fixes #1855
Patch from Christian Maeder

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