Fix build when PROF_SPIN is unset
Fix build when PROF_SPIN is unset

whitehole_spin is only defined when PROF_SPIN is set.

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