[libObject][NFC] Use sys::path::convert_to_slash.

Summary: As suggested in rL353995

Reviewers: compnerd

Reviewed By: compnerd

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58298

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354364 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Object/ArchiveWriter.cpp b/lib/Object/ArchiveWriter.cpp
index 4116ed4..1092b9d 100644
--- a/lib/Object/ArchiveWriter.cpp
+++ b/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,