WindowsCMake\Asan.cmake doesn't work with a VS generator

```cmake
    set(ASAN_LIB_PATH "${VS_TOOLSET_PATH}/lib/${CMAKE_VS_PLATFORM_TOOLSET_ARCHITECTURE}")
    set(ASAN_DLL_PATH "${VS_TOOLSET_PATH}/bin/Host${CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE}/${CMAKE_VS_PLATFORM_TOOLSET_ARCHITECTURE}")
```

Depends on `VS_TOOLSET_PATH` and `CMAKE_VS_PLATFORM_TOOLSET_ARCHITECTURE` which aren't necessarily set by a VS Generator.
