[llvm] [gn build] Port bd338806e423 (PR #207455)

[Nico Weber via llvm-commits]

https://github.com/nico created https://github.com/llvm/llvm-project/pull/207455

None

>From 875b90ee382e5dc14cc796e15cba60c680d6f2e9 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis at chromium.org>
Date: Fri, 3 Jul 2026 21:32:28 +0200
Subject: [PATCH] [gn build] Port bd338806e423

---
 llvm/utils/gn/secondary/libcxx/include/BUILD.gn | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
index e2f351bb0b532..3964f008b456b 100644
--- a/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
+++ b/llvm/utils/gn/secondary/libcxx/include/BUILD.gn
@@ -1613,6 +1613,7 @@ if (current_toolchain == default_toolchain) {
       "__vector/comparison.h",
       "__vector/container_traits.h",
       "__vector/erase.h",
+      "__vector/layout.h",
       "__vector/pmr.h",
       "__vector/swap.h",
       "__vector/vector.h",