GhcMake: Clang/ASSERT fix
GhcMake: Clang/ASSERT fix

Test Plan: Build with clang

Reviewers: thomie, rwbarton, austin, bgamari

Reviewed By: bgamari

Differential Revision: https://phabricator.haskell.org/D1977

sdiehl/ghc,vikraman/ghc,mcschroeder/ghc,shlevy/ghc,sdiehl/ghc,vikraman/ghc,sgillespie/ghc,mettekou/ghc,olsner/ghc,mcschroeder/ghc,shlevy/ghc,olsner/ghc,mettekou/ghc,vikraman/ghc,sdiehl/ghc,mcschroeder/ghc,mcschroeder/ghc,mettekou/ghc,vTurbine/ghc,sgillespie/ghc,tjakway/ghcjvm,ezyang/ghc,tjakway/ghcjvm,mcschroeder/ghc,mettekou/ghc,ezyang/ghc,vikraman/ghc,tjakway/ghcjvm,vikraman/ghc,sgillespie/ghc,snoyberg/ghc,sdiehl/ghc,snoyberg/ghc,vTurbine/ghc,ezyang/ghc,olsner/ghc,mettekou/ghc,olsner/ghc,ezyang/ghc,shlevy/ghc,sgillespie/ghc,tjakway/ghcjvm,vTurbine/ghc,snoyberg/ghc,sgillespie/ghc,mcschroeder/ghc,ezyang/ghc,ezyang/ghc,shlevy/ghc,shlevy/ghc,shlevy/ghc,mettekou/ghc,sdiehl/ghc,snoyberg/ghc,mettekou/ghc,sgillespie/ghc,snoyberg/ghc,snoyberg/ghc,vikraman/ghc,sdiehl/ghc,shlevy/ghc,mcschroeder/ghc,ezyang/ghc,vTurbine/ghc,tjakway/ghcjvm,tjakway/ghcjvm,olsner/ghc,snoyberg/ghc,olsner/ghc,tjakway/ghcjvm,vTurbine/ghc,vTurbine/ghc,vikraman/ghc,sdiehl/ghc,vTurbine/ghc,olsner/ghc,sgillespie/ghc