Subzero: Use "auto" per (unwritten) auto coding style.

src/IceOperand.cpp

 //===- subzero/src/IceOperand.cpp - High-level operand implementation -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 311 matching lines @@
 
   for (Inst &I : Node->getPhis()) {
     if (I.isDeleted())
       continue;
     if (Variable *Dest = I.getDest()) {
       SizeT DestNum = Dest->getIndex();
       assert(DestNum < Metadata.size());
       Metadata[DestNum].markDef(Kind, &I, Node);
     }
     for (SizeT SrcNum = 0; SrcNum < I.getSrcSize(); ++SrcNum) {
-      if (const Variable *Var = llvm::dyn_cast<Variable>(I.getSrc(SrcNum))) {
+      if (auto *Var = llvm::dyn_cast<Variable>(I.getSrc(SrcNum))) {
         SizeT VarNum = Var->getIndex();
         assert(VarNum < Metadata.size());
         constexpr bool IsImplicit = false;
         Metadata[VarNum].markUse(Kind, &I, Node, IsImplicit);
       }
     }
   }
 
   for (Inst &I : Node->getInsts()) {
     if (I.isDeleted())
@@ skipping 204 matching lines @@
   if (getType() != IceType_i32 && getType() != IceType_i16 &&
       getType() != IceType_i8)
     return false;
   // The Following checks if the signed representation of Value is between
   // -Threshold/2 and +Threshold/2
   bool largerThanThreshold = Threshold / 2 + Value >= Threshold;
   return largerThanThreshold;
 }
 
 } // end of namespace Ice