Subzero: Fix some -Winconsistent-missing-override that clang 3.6 warns about.

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 162 matching lines @@
                                   int32_t RegNum = Variable::NoRegister);
   Variable *makeVectorOfHighOrderBits(Type Ty,
                                       int32_t RegNum = Variable::NoRegister);
 
   // Return a memory operand corresponding to a stack allocated Variable.
   OperandX8632Mem *getMemoryOperandForStackSlot(Type Ty, Variable *Slot,
                                                 uint32_t Offset = 0);
 
   void makeRandomRegisterPermutation(
       llvm::SmallVectorImpl<int32_t> &Permutation,
-      const llvm::SmallBitVector &ExcludeRegisters) const;
+      const llvm::SmallBitVector &ExcludeRegisters) const override;
 
   // The following are helpers that insert lowered x86 instructions
   // with minimal syntactic overhead, so that the lowering code can
   // look as close to assembly as practical.
   void _adc(Variable *Dest, Operand *Src0) {
     Context.insert(InstX8632Adc::create(Func, Dest, Src0));
   }
   void _add(Variable *Dest, Operand *Src0) {
     Context.insert(InstX8632Add::create(Func, Dest, Src0));
   }
@@ skipping 316 matching lines @@
 };
 
 template <> void ConstantInteger32::emit(GlobalContext *Ctx) const;
 template <> void ConstantInteger64::emit(GlobalContext *Ctx) const;
 template <> void ConstantFloat::emit(GlobalContext *Ctx) const;
 template <> void ConstantDouble::emit(GlobalContext *Ctx) const;
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX8632_H