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

src/IceTargetLoweringX8632.h

 //===- subzero/src/IceTargetLoweringX8632.h - x86-32 lowering ---*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the TargetLoweringX8632 class, which
@@ skipping 569 matching lines @@
 class TargetDataX8632 final : public TargetDataLowering {
   TargetDataX8632() = delete;
   TargetDataX8632(const TargetDataX8632 &) = delete;
   TargetDataX8632 &operator=(const TargetDataX8632 &) = delete;
 
 public:
   static std::unique_ptr<TargetDataLowering> create(GlobalContext *Ctx) {
     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);
 
 private:
   ~TargetDataX8632() override {}
   template <typename T> static void emitConstantPool(GlobalContext *Ctx);
 };
 
 class TargetHeaderX8632 final : public TargetHeaderLowering {
   TargetHeaderX8632() = delete;
   TargetHeaderX8632(const TargetHeaderX8632 &) = delete;
   TargetHeaderX8632 &operator=(const TargetHeaderX8632 &) = delete;
 
 public:
   static std::unique_ptr<TargetHeaderLowering> create(GlobalContext *Ctx) {
     return std::unique_ptr<TargetHeaderLowering>(new TargetHeaderX8632(Ctx));
   }
 
 protected:
   explicit TargetHeaderX8632(GlobalContext *Ctx);
 
 private:
   ~TargetHeaderX8632() = default;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX8632_H