message: Re-apply protobuf fix for JavaScript builds
  original commit:
  JavaScript bindings for dnn module
diff: @@ -239,8 +239,7 @@ static const uint64 kuint64max = GOOGLE_ULONGLONG(0xFFFFFFFFFFFFFFFF);
  #if defined(__clang__) && defined(__has_cpp_attribute) \
  && !defined(GOOGLE_PROTOBUF_OS_APPLE)
  -# if defined(GOOGLE_PROTOBUF_OS_NACL) || defined(EMSCRIPTEN) || \
  - __has_cpp_attribute(clang::fallthrough)
  +# if defined(GOOGLE_PROTOBUF_OS_NACL) || __has_cpp_attribute(clang::fallthrough)
  # define GOOGLE_FALLTHROUGH_INTENDED [[clang::fallthrough]]
  # endif
  #elif defined(__GNUC__) && __GNUC__ > 6
  