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

src/IceInst.h

 //===- subzero/src/IceInst.h - High-level instructions ----------*- 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 Inst class and its target-independent
@@ skipping 353 matching lines @@
     const bool HasSideEffects = true;
     const InstKind Kind = Inst::Call;
     return new (Func->allocate<InstCall>()) InstCall(
         Func, NumArgs, Dest, CallTarget, HasTailCall, HasSideEffects, Kind);
   }
   void addArg(Operand *Arg) { addSource(Arg); }
   Operand *getCallTarget() const { return getSrc(0); }
   Operand *getArg(SizeT I) const { return getSrc(I + 1); }
   SizeT getNumArgs() const { return getSrcSize() - 1; }
   bool isTailcall() const { return HasTailCall; }
-  void dump(const Cfg *Func) const;
+  void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return Inst->getKind() == Call; }
   Type getReturnType() const;
 
 protected:
   InstCall(Cfg *Func, SizeT NumArgs, Variable *Dest, Operand *CallTarget,
            bool HasTailCall, bool HasSideEff, InstKind Kind)
       : InstHighLevel(Func, Kind, NumArgs + 1, Dest), HasTailCall(HasTailCall) {
     HasSideEffects = HasSideEff;
     addSource(CallTarget);
   }
@@ skipping 480 matching lines @@
   static void noteHead(Ice::Inst *, Ice::Inst *) {}
   void deleteNode(Ice::Inst *) {}
 
 private:
   mutable ilist_half_node<Ice::Inst> Sentinel;
 };
 
 } // end of namespace llvm
 
 #endif // SUBZERO_SRC_ICEINST_H