ogc: add gamecube workflow

.github/workflows/ngc.yml

@@ -0,0 +1,46 @@
+name: Build (Nintendo GameCube)
+
+on: [push, pull_request]
+
+jobs:
+  ngcn:
+    runs-on: ubuntu-latest
+    container:
+      image: devkitpro/devkitppc:latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install build requirements
+        run: |
+          apt update
+          apt install ninja-build
+      - name: Configure CMake
+        run: |
+          /opt/devkitpro/portlibs/gamecube/bin/powerpc-eabi-cmake -S . -B build -G Ninja \
+      - name: Build
+        run: cmake --build build --verbose --parallel
+      - name: Install CMake
+        run: |
+          echo "SDL2_DIR=$(pwd)/prefix" >> $GITHUB_ENV
+          cmake --install build/
+          ( cd prefix; find ) | LC_ALL=C sort -u
+      - name: Verify CMake configuration files
+        run: |
+          /opt/devkitpro/portlibs/gamecube/bin/powerpc-eabi-cmake -S cmake/test -B cmake_config_build -G Ninja \
+            -DTEST_SHARED=FALSE \
+            -DCMAKE_PREFIX_PATH=${{ env.SDL2_DIR }} \
+            -DCMAKE_BUILD_TYPE=Release
+          cmake --build cmake_config_build --verbose
+      - name: Extract CC/CXX/CFLAGS/CXXFLAGS from CMake toolchain
+        run: |
+          /opt/devkitpro/portlibs/gamecube/bin/powerpc-eabi-cmake -S .github/cmake -B /tmp/cmake_extract \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DVAR_PATH=/tmp/ngc_env.txt
+          cat /tmp/ngc_env.txt >> $GITHUB_ENV
+      - name: Verify sdl2-config
+        run: |
+          export PATH=${{ env.SDL2_DIR }}/bin:$PATH
+          cmake/test/test_sdlconfig.sh
+      - name: Verify sdl2.pc
+        run: |
+          export PKG_CONFIG_PATH=${{ env.SDL2_DIR }}/lib/pkgconfig
+          cmake/test/test_pkgconfig.sh