JackeyLove1

Bugfix: fix compiler linker can't find std::filesystem

2

In some compilers that support only some C++17 features like gcc6.3.0, it may encounter a situation where std filesystem lib can't be found, like: ``` /usr/bin/ld: CMakeFiles/gemma.dir/gemma.cc.o: in function `std::filesystem::__cxx11::path::path(std::__cxx11::basic_string...