Subzero. X86. Fixes bundle lock/unlock.

src/IceTargetLoweringX86Base.h

 //===- subzero/src/IceTargetLoweringX86Base.h - x86 lowering ----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 451 matching lines @@
   public:
     std::unique_ptr<AutoBundle> Bundler;
     X86OperandMem **const MemOperand;
 
     template <typename... T>
     AutoMemorySandboxer(typename Traits::TargetLowering *Target, T... Args)
         : Target(Target), MemOperand(Target->SandboxingType == ST_None
                                          ? nullptr
                                          : findMemoryReference(Args...)) {
       if (MemOperand != nullptr) {
-        Bundler = makeUnique<AutoBundle>(Target, BundleLockOpt);
+        if (Traits::Is64Bit) {
+          Bundler = makeUnique<AutoBundle>(Target, BundleLockOpt);
+        }
         *MemOperand = Target->_sandbox_mem_reference(*MemOperand);
       }
     }
 
     ~AutoMemorySandboxer() {}
   };
 
   /// The following are helpers that insert lowered x86 instructions with
   /// minimal syntactic overhead, so that the lowering code can look as close to
   /// assembly as practical.
@@ skipping 636 matching lines @@
 
   explicit TargetHeaderX86(GlobalContext *Ctx) : TargetHeaderLowering(Ctx) {}
 };
 
 } // end of namespace X86NAMESPACE
 } // end of namespace Ice
 
 #include "IceTargetLoweringX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASE_H