Fix a bug that would cause subzero to fail when --threads=0.

src/IceTargetLoweringX8632.h

Index: src/IceTargetLoweringX8632.h
diff --git a/src/IceTargetLoweringX8632.h b/src/IceTargetLoweringX8632.h
index 0b46e1bde9201aa44f389b900e144beee94f9549..6ba687779dac3a9f3315afd8fd2520d5678b02f5 100644
--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -587,8 +587,9 @@ public:
     return std::unique_ptr<TargetDataLowering>(new TargetDataX8632(Ctx));
   }
 
-  void lowerGlobals(std::unique_ptr<VariableDeclarationList> Vars) override;
-  void lowerConstants() override;
+  void lowerGlobals(const VariableDeclarationList &Vars,
+                    const IceString &SectionSuffix) override;
+  void lowerConstants(const IceString &SectionSuffix) override;
 
 protected:
   explicit TargetDataX8632(GlobalContext *Ctx);