Index: llvm/trunk/lib/Object/ArchiveWriter.cpp
===================================================================
--- llvm/trunk/lib/Object/ArchiveWriter.cpp
+++ llvm/trunk/lib/Object/ArchiveWriter.cpp
@@ -514,13 +514,9 @@
   for (auto ToE = sys::path::end(To); ToI != ToE; ++ToI)
     sys::path::append(Relative, *ToI);
 
-#ifdef _WIN32
   // Replace backslashes with slashes so that the path is portable between *nix
   // and Windows.
-  std::replace(Relative.begin(), Relative.end(), '\\', '/');
-#endif
-
-  return Relative.str();
+  return sys::path::convert_to_slash(Relative);
 }
 
 Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers,