ci/appveyor: test build on MSVC

.appveyor.yml

@@ -0,0 +1,54 @@
+# Documentation: https://wiki.unvanquished.net/wiki/Continuous_integration
+
+skip_branch_with_pr: true
+
+only_commits:
+  files:
+    - .appveyor.yml
+    - example1/
+    - example2/
+    - example3/
+    # The rest of this list should stay in sync with azure-pipelines.yml
+    - crunch/
+    - crnlib/
+    - inc/
+    - cmake/
+    - CMakeLists.txt
+
+environment:
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      generator: Visual Studio 16 2019
+      platform: x64
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      generator: Visual Studio 16 2019
+      platform: win32
+
+build:
+  parallel: true
+
+build_script:
+  # simple line break: space
+  # double line break: line break
+
+  # The CFLAGS/CXXFLAGS env vars *prepend* to CMAKE_<lang>_FLAGS rather than overwriting.
+  # /Wv pins warnings to a specific compiler version so that new ones
+  # don't make the build error after Appveyor updates the compiler.
+
+  # The CMAKE_CONFIGURATION_TYPES CMake option make sure to not uselessly provide
+  # build configurations that will not be used.
+  - cmd: >
+      echo %NUMBER_OF_PROCESSORS%
+
+      set CMAKE_BUILD_PARALLEL_LEVEL=%NUMBER_OF_PROCESSORS%
+
+      cmake --version
+
+      set CFLAGS=/Wv:19.29.30037
+
+      set CXXFLAGS=/Wv:19.29.30037
+
+      cmake -Wdev -G"%generator%" -A"%platform%" -S. -Bbuild -DCMAKE_CONFIGURATION_TYPES=Release
+      -DBUILD_CRUNCH=ON -DBUILD_SHARED_LIBCRN=ON -DBUILD_EXAMPLES=ON
+
+      cmake --build build --config Release