Fix ffi build on amd64/Linux, and simplify a little more
Fix ffi build on amd64/Linux, and simplify a little more

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