message: Use -mssse3 flag with clang-cl
diff: @@ -28,6 +28,11 @@ else()
  target_compile_options(meshoptimizer PRIVATE -Wall -Wextra -Werror)
  endif()
  +if(CLANG_CL)
  + # Clang for Windows needs an additional flag for SSSE3 instructions.
  + target_compile_options(meshoptimizer PRIVATE -mssse3)
  +endif()
  +
  if(BUILD_DEMO)
  add_executable(demo demo/main.cpp demo/miniz.cpp demo/objparser.cpp)
  target_link_libraries(demo meshoptimizer)
  