Document -fwarn-pointless-pragmas; fixes #8049
Document -fwarn-pointless-pragmas; fixes #8049

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