Document the -fwarn-unsupported-calling-conventions flag
Document the -fwarn-unsupported-calling-conventions flag

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