Subzero: Emit functions and global initializers in a separate thread.

src/IceTargetLoweringX8632.h

Index: src/IceTargetLoweringX8632.h
diff --git a/src/IceTargetLoweringX8632.h b/src/IceTargetLoweringX8632.h
index fca29c43d7f4eb65f20f1cc842a26aea0ffeeb9a..543183ed1139aeadfab9a975dda8b8bca53ba592 100644
--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -497,14 +497,14 @@ public:
     return new TargetDataX8632(Ctx);
   }
 
-  void lowerGlobal(const VariableDeclaration &Var) const final;
-  void lowerGlobalsELF(const VariableDeclarationList &Vars) const final;
-  void lowerConstants(GlobalContext *Ctx) const final;
+  void lowerGlobals(std::unique_ptr<VariableDeclarationList> Vars) const final;
+  void lowerConstants() const final;
 
 protected:
   TargetDataX8632(GlobalContext *Ctx);
 
 private:
+  void lowerGlobal(const VariableDeclaration &Var) const;
   ~TargetDataX8632() override {}
   template <typename T> static void emitConstantPool(GlobalContext *Ctx);
 };