Revert "Disable windows-mingw builder temporarily"

.github/workflows/windows-mingw.yml

@@ -0,0 +1,54 @@
+name: CI (Windows-mingw)
+
+on: [push, pull_request]
+
+env:
+  OPENSSL_DIR: d:\a\_temp\msys\msys64\usr
+
+jobs:
+  build_and_test:
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - stable
+          - nightly
+
+    name: ${{ matrix.version }} - x86_64-pc-windows-gnu
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@master
+
+      - name: Install ${{ matrix.version }}
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.version }}-x86_64-pc-windows-gnu
+          profile: minimal
+          override: true
+
+      - name: Install MSYS2
+        uses: numworks/setup-msys2@v1
+
+      - name: Install OpenSSL
+        run: |
+          msys2do pacman --noconfirm -S openssl-devel pkg-config
+
+      - name: Copy and check libs
+        run: |
+          Copy-Item d:\a\_temp\msys\msys64\usr\lib\libssl.dll.a d:\a\_temp\msys\msys64\usr\lib\libssl.dll
+          Copy-Item d:\a\_temp\msys\msys64\usr\lib\libcrypto.dll.a d:\a\_temp\msys\msys64\usr\lib\libcrypto.dll
+          Get-ChildItem d:\a\_temp\msys\msys64\usr\lib
+          Get-ChildItem d:\a\_temp\msys\msys64\usr
+
+      - name: check build
+        uses: actions-rs/cargo@v1
+        with:
+          command: check
+          args: --all --bins --examples --tests
+
+      - name: tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --all --all-features --no-fail-fast -- --nocapture