Disable MSYS tests and add MacOS tests.

.github/workflows/main.yml

@@ -42,6 +42,7 @@ jobs:
 
   build-msys2-clang:
     runs-on: windows-latest
+    if: ${{ false }}
     strategy:
       matrix:
         build_type: [Release, Debug]
@@ -114,3 +115,38 @@ jobs:
         run: |
           cd test
           python3 src/tester.py ../build/c3c test_suite/
+
+  build-mac:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        build_type: [Release, Debug]
+        llvm_version: [12]
+
+      # Don't abort runners if a single one fails
+      fail-fast: false
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: Download LLVM, botan and setup PATH
+        run: |
+          brew install llvm@${{ matrix.llvm_version }} botan
+          echo "/usr/local/opt/llvm@${{ matrix.llvm_version }}/bin" >> $GITHUB_PATH
+          TMP_PATH=$(xcrun --show-sdk-path)/user/include
+          echo "CPATH=$TMP_PATH" >> $GITHUB_ENV
+
+      - name: CMake
+        run: |
+          mkdir build && cd build
+          cmake .. -DC3_LLVM_VERSION=${{matrix.llvm_version}} -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+          cmake --build .
+
+      - name: Build testproject
+        run: |
+          cd resources/testproject
+          ../../build/c3c build --debug-log
+
+      - name: run compiler tests
+        run: |
+          cd test
+          python3 src/tester.py ../build/c3c test_suite/