[llvm] [libcxx] [libc++] Use GitHub-provided runners for the windows CI (PR #79326)

[Nikolas Klauser via llvm-commits]

https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/79326

>From e91ba8f405d8820ac8dae2350bd17c04401d5b8c Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Wed, 24 Jan 2024 17:42:53 +0100
Subject: [PATCH] [libc++] Use GitHub-provided runners for the windows CI

---
 .github/workflows/libcxx-build-and-test.yaml | 6 ++++++
 libcxx/trigger                               | 0
 2 files changed, 6 insertions(+)
 create mode 100644 libcxx/trigger

diff --git a/.github/workflows/libcxx-build-and-test.yaml b/.github/workflows/libcxx-build-and-test.yaml
index 5727b956dc6dd23..130b331e646a384 100644
--- a/.github/workflows/libcxx-build-and-test.yaml
+++ b/.github/workflows/libcxx-build-and-test.yaml
@@ -199,3 +199,9 @@ jobs:
             **/CMakeError.log
             **/CMakeOutput.log
             **/crash_diagnostics/*
+  windows:
+    runs-on: windows-2019
+    steps:
+      - uses: actions/checkout at v4
+      - name: clang-cl (DLL)
+        run: libcxx/utils/ci/run-buildbot clang-cl-dll
diff --git a/libcxx/trigger b/libcxx/trigger
new file mode 100644
index 000000000000000..e69de29bb2d1d64