CI: add Windows run

Author: hishamhm

.github/workflows/ci.yml

@@ -13,11 +13,22 @@ jobs:
         - os: "macos-latest"
           lua-version: "5.4"
           libflag: "-bundle -undefined dynamic_lookup -all_load --coverage"
+        - os: "windows-latest"
+          toolchain: "msvc"
+          lua-version: "5.4"
+        - os: "windows-latest"
+          lua-version: "luajit"
     runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@master
 
+    - name: Setup MSVC
+      # 'luarocks/gh-actions-lua' step requires msvc to build PUC-Rio Lua
+      # versions on Windows (LuaJIT will be built using MinGW/gcc).
+      if: ${{ matrix.toolchain == 'msvc' }}
+      uses: ilammy/msvc-dev-cmd@v1
+
     - uses: luarocks/gh-actions-lua@master
       with:
         luaVersion: ${{ matrix.lua-version }}
@@ -33,15 +44,24 @@ jobs:
         # install luacov-coveralls, but avoid installing luafilesystem
         luarocks install luacov-coveralls --server=https://luarocks.org/dev --deps-mode=none
 
-    - name: Build
+    - name: Unix Build
+      if: ${{ matrix.os != 'windows-latest' }}
       run: |
         luarocks make CFLAGS="-O2 -fPIC -ftest-coverage -fprofile-arcs" LIBFLAG="${{ matrix.libflag }}"
 
+    - name: Windows Build
+      # TODO Windows coverage
+      if: ${{ matrix.os == 'windows-latest' }}
+      run: |
+        luarocks make
+
     - name: Test
       run: |
         lua -lluacov tests/test.lua
 
     - name: Coverage
+      # TODO Windows coverage
+      if: ${{ matrix.os != 'windows-latest' }}
       run: |
         export MY_PYTHON_VER=$(python -c 'import sys; print(".".join(sys.version.split(".")[0:2]))')
         export PATH="/Users/runner/Library/Python/$MY_PYTHON_VER/bin:$PATH"