Add Windows to the actions

Author: amadvance

.github/workflows/github-actions-build.yml

@@ -24,4 +24,20 @@ jobs:
       - run: ./configure --enable-warning-as-error
       - run: make all
       - run: make dist
+  build-win:
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: msys2 {0}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: MINGW64
+          update: true
+          install: mingw-w64-x86_64-gcc autoconf automake make
+      - run: autoreconf -i
+      - run: ./configure --enable-warning-as-error
+      - run: make all
+      - run: make dist