Add llvm libcxx package.

llvm-libcxx-16.yaml

@@ -0,0 +1,77 @@
+package:
+  name: llvm-libcxx-16
+  version: 16.0.6
+  epoch: 0
+  description: The LLVM libc++ libraries
+  copyright:
+    - license: Apache-2.0
+  dependencies:
+    provides:
+      - llvm-libcxx=16
+
+environment:
+  contents:
+    packages:
+      - busybox
+      - ca-certificates-bundle
+      - build-base
+      - automake
+      - autoconf
+      - cmake
+      - samurai
+      - git
+      - python3
+      - curl
+      - clang
+      - libstdc++-dev
+
+pipeline:
+  - uses: git-checkout
+    with:
+      repository: https://github.com/llvm/llvm-project
+      tag: llvmorg-${{package.version}}
+      expected-commit: 7cbf1a2591520c2491aa35339f227775f4d3adf6
+
+  - runs: |
+      gccver=$(gcc -dumpversion)
+      CC=clang CXX=clang cmake -G Ninja -S runtimes -B build \
+        -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi" \
+        -DCMAKE_INSTALL_PREFIX=/usr \
+        -DLLVM_INCLUDE_TESTS=OFF \
+        -DLIBCXX_INCLUDE_BENCHMARKS=OFF \
+        -DLIBCXX_CXX_ABI=libstdc++ \
+        -DLLVM_BUILD_LLVM_DYLIB=ON \
+        -DLIBCXX_CXX_ABI_INCLUDE_PATHS=/usr/include/c++/$gccver/
+
+  - runs: |
+      cmake --build build
+
+  - runs: |
+      DESTDIR=${{targets.destdir}} cmake --install build
+
+  - uses: strip
+
+subpackages:
+  - name: llvm-libcxx-16-dev
+    pipeline:
+      - uses: split/dev
+    dependencies:
+      provides:
+        - llvm-libcxx-dev=16
+
+  - name: llvm-libcxxabi-16
+    pipeline:
+      - runs: |
+          mkdir -p ${{targets.subpkgdir}}/usr/lib
+          mv ${{targets.destdir}}/usr/lib/libc++abi.so* ${{targets.subpkgdir}}/usr/lib/
+    dependencies:
+      provides:
+        - llvm-libcxxabi=16
+
+update:
+  enabled: true
+  github:
+    identifier: llvm/llvm-project
+    use-tag: true
+    tag-filter: llvmorg-16.
+    strip-prefix: llvmorg-