ClangPchManager: Fix path for excluded include files

Still used the old approach but now it is using the new one.

Change-Id: I4bf4da3a5d41d46afff261f3d77bd9190737038a
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/tools/clangrefactoringbackend/source/clangtool.cpp

@@ -57,7 +57,7 @@ void ClangTool::addUnsavedFiles(const V2::FileContainers &unsavedFiles)
     m_unsavedFileContents.reserve(m_unsavedFileContents.size() + unsavedFiles.size());
 
     auto convertToUnsavedFileContent = [](const V2::FileContainer &unsavedFile) {
-        return UnsavedFileContent{unsavedFile.filePath.clone(),
+        return UnsavedFileContent{NativeFilePath{unsavedFile.filePath},
                                   unsavedFile.unsavedFileContent.clone()};
     };