Add a getTarget method that returns the x86 target lowering

src/IceInstX86Base.h

 //===- subzero/src/IceInstX86Base.h - Generic x86 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 17 matching lines @@
 
 template <class Machine> struct MachineTraits;
 
 template <class Machine> class InstX86Base : public InstTarget {
   InstX86Base<Machine>() = delete;
   InstX86Base<Machine>(const InstX86Base &) = delete;
   InstX86Base &operator=(const InstX86Base &) = delete;
 
 public:
   using Traits = MachineTraits<Machine>;
+  using X86TargetLowering = typename Traits::TargetLowering;
 
   enum InstKindX86 {
     k__Start = Inst::Target,
     Adc,
     AdcRMW,
     Add,
     AddRMW,
     Addps,
     Addss,
     Adjuststack,
@@ skipping 101 matching lines @@
 
   // Shared emit routines for common forms of instructions.
   static void emitTwoAddress(const char *Opcode, const Inst *Inst,
                              const Cfg *Func);
 
   static void
   emitIASGPRShift(const Cfg *Func, Type Ty, const Variable *Var,
                   const Operand *Src,
                   const typename Traits::Assembler::GPREmitterShiftOp &Emitter);
 
+  static X86TargetLowering *getTarget(const Cfg* Func) {
+    return static_cast<X86TargetLowering *>(Func->getTarget());
+  }
+
 protected:
   InstX86Base<Machine>(Cfg *Func, InstKindX86 Kind, SizeT Maxsrcs,
                        Variable *Dest)
       : InstTarget(Func, static_cast<InstKind>(Kind), Maxsrcs, Dest) {}
 
   static bool isClassof(const Inst *Inst, InstKindX86 MyKind) {
     return Inst->getKind() == static_cast<InstKind>(MyKind);
   }
   // Most instructions that operate on vector arguments require vector memory
   // operands to be fully aligned (16-byte alignment for PNaCl vector types).
@@ skipping 3068 matching lines @@
           &InstX86Base<Machine>::Traits::Assembler::psrl};                     \
   }                                                                            \
   }
 
 } // end of namespace X86Internal
 } // end of namespace Ice
 
 #include "IceInstX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICEINSTX86BASE_H