Subzero: Provide missing isMemoryWrite() method.

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.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 961 matching lines @@
   void addIndex(ConstantInteger32 *Index) {
     assert(CurrentIndex < NumIndexes);
     Indexes[CurrentIndex++] = Index;
   }
 
   ConstantInteger32 *getIndex(SizeT Pos) const {
     assert(Pos < NumIndexes);
     return Indexes[Pos];
   }
 
+  bool isMemoryWrite() const override { return false; }
   void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Instr) {
     return Instr->getKind() == ShuffleVector;
   }
 
 private:
   InstShuffleVector(Cfg *Func, Variable *Dest, Variable *Src0, Variable *Src1);
 
   void destroy(Cfg *Func) override {
     Func->deallocateArrayOf<ConstantInteger32 *>(Indexes);
@@ skipping 132 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