CI: Add build on Windows using gcc toolchain

Author: jon-turney

.github/workflows/ci.yml

@@ -28,3 +28,17 @@ jobs:
         run:  |
           cd build
           make test
+
+  win32:
+    runs-on: windows-latest
+    steps:
+      - run: git config --global core.autocrlf input
+      - uses: actions/checkout@v2
+      - uses: msys2/setup-msys2@v2
+      - name: Build
+        shell: msys2 {0}
+        run: |
+          mkdir build
+          cd build
+          cmake -DENABLE_STATIC=ON -DWITHOUT_COOKIEOPEN=ON ..
+          make