isAlive needs to look through BLACKHOLE indirections
isAlive needs to look through BLACKHOLE indirections

This has been breaking StableNames and possibly weak pointers in some
cases.

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