Use msys2 on Windows in github actions

Author: coot

.github/workflows/haskell.yml

@@ -12,10 +12,29 @@ jobs:
         ghc: ["8.10.7", "9.2.2"]
         os: [ubuntu-latest, macos-latest, windows-latest]
 
+    defaults:
+      run:
+        shell: ${{ matrix.os == 'windows-latest' && 'msys2 {0}' || 'bash' }}
+
     steps:
     - name: Set cache versioj
       run: echo "CACHE_VERSION=pu4Aevoo" >> $GITHUB_ENV
 
+    steps:
+    - name: "WIN: Setup MSYS2 and libraries"
+      if: runner.os == 'Windows'
+      uses: msys2/setup-msys2@v2
+      with:
+        update: true
+        install: >-
+          base-devel
+          autoconf-wrapper
+          autoconf
+          automake
+          libtool
+          make
+          git
+
     - name: "Setup haskell"
       uses: haskell/actions/setup@v1
       id: setup-haskell