[gn build] Port 0be1883c36fc
diff --git a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
index 0586704..1b73f37 100644
--- a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
+++ b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
@@ -430,6 +430,8 @@
"__filesystem/recursive_directory_iterator.h",
"__filesystem/space_info.h",
"__filesystem/u8path.h",
+ "__flat_map/flat_map.h",
+ "__flat_map/sorted_unique.h",
"__format/buffer.h",
"__format/concepts.h",
"__format/container_adaptor.h",