File set-revision.patch of Package llvm

--- tools/clang/lib/Basic/Version.cpp	(revision 131788)
+++ tools/clang/lib/Basic/Version.cpp	(working copy)
@@ -50,11 +50,7 @@
 }
 
 std::string getClangRevision() {
-#ifdef SVN_REVISION
   return SVN_REVISION;
-#else
-  return "";
-#endif
 }
 
 std::string getClangFullRepositoryVersion() {