Fix for Windows, and delete the .mk file if ghc-config fails
Fix for Windows, and delete the .mk file if ghc-config fails

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