[Refactor Xcode Objects] Enable generating per file '--help' compiler flag

tools/gn/xcode_writer.cc

Index: tools/gn/xcode_writer.cc
diff --git a/tools/gn/xcode_writer.cc b/tools/gn/xcode_writer.cc
index b0526836a6928a2780cf5a279f1c21e0c982be9b..b35cb44e2e049113ab24a00903d80c77f85246ad 100644
--- a/tools/gn/xcode_writer.cc
+++ b/tools/gn/xcode_writer.cc
@@ -353,8 +353,8 @@ void XcodeWriter::CreateSourcesProject(
   for (const SourceFile& source : sources) {
     std::string source_file =
         RebasePath(source.value(), source_dir, absolute_source_path);
-    sources_for_indexing->AddSourceFileToIndexingTarget(source_file,
-                                                        source_file);
+    sources_for_indexing->AddSourceFileToIndexingTarget(
+        source_file, source_file, CompilerFlags::NONE);
   }
 
   projects_.push_back(std::move(sources_for_indexing));