fix for a deadlock when using +RTS -hb with -prof -threaded
fix for a deadlock when using +RTS -hb with -prof -threaded

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