Appveyor: enable warning-as-error compile option

Author: TheMostDiligent

appveyor.yml

@@ -37,7 +37,7 @@ before_build:
   - echo add_subdirectory(DiligentCore) >> CMakeLists.txt
   - echo add_subdirectory(DiligentTools) >> CMakeLists.txt
   - echo %PLATFORM%
-  - cmake -S . -B ./build -D DILIGENT_BUILD_TOOLS_TESTS=TRUE -D DILIGENT_MSVC_RELEASE_COMPILE_OPTIONS="/arch:AVX2" -G "Visual Studio 16 2019" -A %PLATFORM%
+  - cmake -S . -B ./build -D DILIGENT_BUILD_TOOLS_TESTS=TRUE -D DILIGENT_MSVC_COMPILE_OPTIONS="/WX" -D DILIGENT_MSVC_RELEASE_COMPILE_OPTIONS="/arch:AVX2" -G "Visual Studio 16 2019" -A %PLATFORM%
 
 build:
   project: c:\projects\build\DiligentTools_Test.sln