Try to get Windows to work

Copied from: https://github.com/gyscos/zstd-rs/blob/614f5d960197a8a98a9f38e617cb2a2b90542d92/.github/workflows/windows.yml#L39-L56

.github/workflows/ci.yml

@@ -168,6 +168,25 @@ jobs:
           profile: minimal
           override: true
 
+      - name: Add mingw32 to path for i686-gnu
+        run: |
+          echo "C:\msys64\mingw32\bin" >> $GITHUB_PATH
+          echo "C:\msys64\usr\bin" >> $GITHUB_PATH
+        if: matrix.target == 'i686-pc-windows-gnu'
+        shell: bash
+      - name: Add mingw64 to path for x86_64-gnu
+        run: |
+          echo "C:\msys64\mingw64\bin" >> $GITHUB_PATH
+          echo "C:\msys64\usr\bin" >> $GITHUB_PATH
+        if: matrix.target == 'x86_64-pc-windows-gnu'
+        shell: bash
+      - name: Update gcc
+        if: matrix.target == 'x86_64-pc-windows-gnu'
+        run: pacman.exe -Sy --noconfirm mingw-w64-x86_64-toolchain
+      - name: Update gcc
+        if: matrix.target == 'i686-pc-windows-gnu'
+        run: pacman.exe -Sy --noconfirm mingw-w64-i686-toolchain
+
       - name: Build
         uses: actions-rs/cargo@v1
         with: