fix 64bit two-stage allocator on Solaris/AMD64 platform (#10790)
fix 64bit two-stage allocator on Solaris/AMD64 platform (#10790)

Test Plan: tested on Solaris 11/AMD64 when previous build failed

Reviewers: bgamari, austin, simonmar, gcampax, ezyang

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1169

acowley/ghc,ml9951/ghc,oldmanmike/ghc,ezyang/ghc,siddhanathan/ghc,GaloisInc/halvm-ghc,snoyberg/ghc,mettekou/ghc,oldmanmike/ghc,gridaphobe/ghc,mettekou/ghc,tjakway/ghcjvm,siddhanathan/ghc,acowley/ghc,mcschroeder/ghc,AlexanderPankiv/ghc,nushio3/ghc,da-x/ghc,mfine/ghc,vTurbine/ghc,mfine/ghc,vTurbine/ghc,ezyang/ghc,GaloisInc/halvm-ghc,nushio3/ghc,nushio3/ghc,snoyberg/ghc,vikraman/ghc,tjakway/ghcjvm,AlexanderPankiv/ghc,siddhanathan/ghc,sgillespie/ghc,shlevy/ghc,vikraman/ghc,oldmanmike/ghc,AlexanderPankiv/ghc,ml9951/ghc,ml9951/ghc,ghc-android/ghc,GaloisInc/halvm-ghc,nkaretnikov/ghc,ml9951/ghc,mcschroeder/ghc,oldmanmike/ghc,ghc-android/ghc,vikraman/ghc,sdiehl/ghc,AlexanderPankiv/ghc,acowley/ghc,olsner/ghc,vikraman/ghc,da-x/ghc,shlevy/ghc,GaloisInc/halvm-ghc,ml9951/ghc,olsner/ghc,gridaphobe/ghc,elieux/ghc,anton-dessiatov/ghc,ghc-android/ghc,gridaphobe/ghc,wxwxwwxxx/ghc,nkaretnikov/ghc,da-x/ghc,GaloisInc/halvm-ghc,nkaretnikov/ghc,AlexanderPankiv/ghc,mfine/ghc,sdiehl/ghc,wxwxwwxxx/ghc,ezyang/ghc,wxwxwwxxx/ghc,acowley/ghc,gridaphobe/ghc,mcschroeder/ghc,sdiehl/ghc,tjakway/ghcjvm,mettekou/ghc,snoyberg/ghc,elieux/ghc,sdiehl/ghc,siddhanathan/ghc,mettekou/ghc,sdiehl/ghc,ml9951/ghc,shlevy/ghc,oldmanmike/ghc,oldmanmike/ghc,sgillespie/ghc,mettekou/ghc,anton-dessiatov/ghc,tjakway/ghcjvm,sdiehl/ghc,nushio3/ghc,ghc-android/ghc,tjakway/ghcjvm,olsner/ghc,mfine/ghc,mcschroeder/ghc,shlevy/ghc,mcschroeder/ghc,siddhanathan/ghc,vikraman/ghc,elieux/ghc,ghc-android/ghc,vikraman/ghc,gridaphobe/ghc,elieux/ghc,mfine/ghc,ghc-android/ghc,gridaphobe/ghc,siddhanathan/ghc,siddhanathan/ghc,elieux/ghc,ezyang/ghc,olsner/ghc,shlevy/ghc,nkaretnikov/ghc,tjakway/ghcjvm,mcschroeder/ghc,mcschroeder/ghc,mfine/ghc,nkaretnikov/ghc,sgillespie/ghc,da-x/ghc,vTurbine/ghc,nushio3/ghc,sgillespie/ghc,vTurbine/ghc,snoyberg/ghc,wxwxwwxxx/ghc,mettekou/ghc,ezyang/ghc,nushio3/ghc,sgillespie/ghc,ezyang/ghc,vTurbine/ghc,vikraman/ghc,vTurbine/ghc,da-x/ghc,acowley/ghc,mfine/ghc,olsner/ghc,AlexanderPankiv/ghc,ezyang/ghc,shlevy/ghc,oldmanmike/ghc,anton-dessiatov/ghc,gridaphobe/ghc,sgillespie/ghc,da-x/ghc,acowley/ghc,anton-dessiatov/ghc,wxwxwwxxx/ghc,olsner/ghc,olsner/ghc,ghc-android/ghc,wxwxwwxxx/ghc,nushio3/ghc,GaloisInc/halvm-ghc,ml9951/ghc,anton-dessiatov/ghc,snoyberg/ghc,acowley/ghc,elieux/ghc,nkaretnikov/ghc,anton-dessiatov/ghc,mettekou/ghc,GaloisInc/halvm-ghc,tjakway/ghcjvm,sdiehl/ghc,ml9951/ghc,da-x/ghc,snoyberg/ghc,shlevy/ghc,anton-dessiatov/ghc,nkaretnikov/ghc,AlexanderPankiv/ghc,elieux/ghc,wxwxwwxxx/ghc,sgillespie/ghc,vTurbine/ghc,snoyberg/ghc