Add Cling GH CI workflow

Author: dpiparo

.github/workflows/cling.yml

@@ -0,0 +1,45 @@
+name: Cling Build and Test
+
+on:
+  push:
+    paths:
+      - '**'
+  workflow_dispatch:
+
+jobs:
+  build-and-test:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    steps:
+      - name: Checkout LLVM
+        uses: actions/checkout@v4
+        with:
+          repository: root-project/llvm-project
+          path: llvm
+          ref: cling-latest
+          fetch-depth: 1
+
+      - name: Checkout Cling
+        uses: actions/checkout@v4
+        with:
+          repository: root-project/cling
+          path: cling
+          fetch-depth: 1
+
+      - name: Prepare build directory
+        run: |
+          mkdir build
+
+      - name: Configure
+        working-directory: build
+        run: cmake -DLLVM_EXTERNAL_PROJECTS=cling -DLLVM_EXTERNAL_CLING_SOURCE_DIR=../cling/ -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_TARGETS_TO_BUILD="host;NVPTX" -DCMAKE_BUILD_TYPE=Release ../llvm/llvm/
+
+      - name: Build
+        working-directory: build
+        run: cmake --build . --parallel 4 --target cling
+
+      - name: Test
+        working-directory: build
+        run: cmake --build . --target check-cling