Subzero: Fix target attribute when SZTARGET is defined.

src/IceRevision.cpp

 //===- subzero/src/IceRevision.cpp - Revision string embedding ------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Implements the function for returning the Subzero revision string.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceRevision.h"
 
-#define XSTRINGIFY(x) STRINGIFY(x)
-#define STRINGIFY(x) #x
+#include "IceDefs.h" // XSTRINGIFY
 
 #ifndef SUBZERO_REVISION
 #define SUBZERO_REVISION unknown
 #endif // !SUBZERO_REVISION
 
 namespace Ice {
 const char *getSubzeroRevision() {
   return "Subzero_revision_" XSTRINGIFY(SUBZERO_REVISION);
 }
 } // end of namespace Ice