Libretro: add build workflow

.github/workflows/libretro.yml

@@ -0,0 +1,71 @@
+name: Libretro Builds
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build-windows:
+    runs-on: windows-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+    - name: Install MSYS2
+      uses: msys2/setup-msys2@v2
+      with:
+        msystem: MINGW64
+        update: true
+    - name: Install build tools
+      run: pacman -S mingw-w64-x86_64-{gcc,pkg-config} make --noconfirm
+      shell: msys2 {0}
+    - name: Compile
+      run: |
+        make libretro -j$(nproc)
+      shell: msys2 {0}
+      working-directory: ${{ github.workspace }}
+    - name: Upload
+      uses: actions/upload-artifact@v2
+      with:
+        name: noods-libretro-windows
+        path: |
+          noods_libretro.dll
+          noods_libretro.info
+
+  build-mac:
+    runs-on: macos-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v1
+    - name: Compile
+      run: |
+        make libretro -j$(sysctl -n hw.logicalcpu)
+    - name: Upload
+      uses: actions/upload-artifact@v2
+      with:
+        name: noods-libretro-mac
+        path: |
+          noods_libretro.dylib
+          noods_libretro.info
+
+  build-linux:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Install build tools
+      run: |
+        sudo apt update
+        sudo apt install gcc -y
+    - name: Checkout
+      uses: actions/checkout@v1
+    - name: Compile
+      run: |
+        git config --global protocol.file.allow always
+        make libretro -j$(nproc)
+    - name: Upload
+      uses: actions/upload-artifact@v2
+      with:
+        name: noods-libretro-linux
+        path: |
+          noods_libretro.so
+          noods_libretro.info