Subzero: Use Cfg::getOptLevel() instead of ClFlags version.

src/IceTargetLowering.cpp

 //===- subzero/src/IceTargetLowering.cpp - Basic lowering implementation --===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 720 matching lines @@
 InstCall *TargetLowering::makeHelperCall(RuntimeHelper FuncID, Variable *Dest,
                                          SizeT MaxSrcs) {
   constexpr bool HasTailCall = false;
   Constant *CallTarget = Ctx->getRuntimeHelperFunc(FuncID);
   InstCall *Call =
       InstCall::create(Func, MaxSrcs, Dest, CallTarget, HasTailCall);
   return Call;
 }
 
 bool TargetLowering::shouldOptimizeMemIntrins() {
-  return getFlags().getOptLevel() >= Opt_1 || getFlags().getForceMemIntrinOpt();
+  return Func->getOptLevel() >= Opt_1 || getFlags().getForceMemIntrinOpt();
 }
 
 void TargetLowering::scalarizeArithmetic(InstArithmetic::OpKind Kind,
                                          Variable *Dest, Operand *Src0,
                                          Operand *Src1) {
   scalarizeInstruction(
       Dest, [this, Kind](Variable *Dest, Operand *Src0, Operand *Src1) {
         return Context.insert<InstArithmetic>(Kind, Dest, Src0, Src1);
       }, Src0, Src1);
 }
@@ skipping 159 matching lines @@
   case TARGET_LOWERING_CLASS_FOR(X):                                           \
     return ::X::createTargetHeaderLowering(Ctx);
 #include "SZTargets.def"
 #undef SUBZERO_TARGET
   }
 }
 
 TargetHeaderLowering::~TargetHeaderLowering() = default;
 
 } // end of namespace Ice