Fix potential `mingw32_HOST_OS` -Werror failure
Fix potential `mingw32_HOST_OS` -Werror failure

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