Add build CI for openmp-target

Author: streeve

.github/workflows/CI.yml

@@ -494,6 +494,7 @@ jobs:
     strategy:
       matrix:
         cxx: ['hipcc']
+        backend: ['HIP', 'OPENMPTARGET']
         cmake_build_type: ['Debug']
         kokkos_ver: ['4.2.00']
     runs-on: ubuntu-latest
@@ -508,12 +509,14 @@ jobs:
       - name: Build kokkos
         working-directory: kokkos
         run: |
+          [[ ${{ matrix.backend }} == "HIP" ]] && kokkos_cmake_opts+=( -DKokkos_ENABLE_HIP==ON )
+          [[ ${{ matrix.backend }} == "OPENMPTARGET" ]] && kokkos_cmake_opts+=( -DKokkos_ENABLE_OPENMPTARGET==ON )
           cmake -B build \
             -DCMAKE_INSTALL_PREFIX=$HOME/kokkos \
             -DCMAKE_CXX_COMPILER=${{ matrix.cxx }} \
             -DCMAKE_BUILD_TYPE=${{ matrix.cmake_build_type }} \
-            -DKokkos_ENABLE_HIP=ON \
-            -DKokkos_ARCH_VEGA908=ON
+            -DKokkos_ARCH_VEGA908=ON \
+            ${kokkos_cmake_opts[@]}
           cmake --build build --parallel 2
           cmake --install build
       - name: Checkout arborx