To be able to link many object files, we must be able to read them! Of course, there is `std::fs`, but we want to be fast right? So let's use mmap.
Oh, it's not available everywhere. So let's use a file picker, don't you mind, which will select the best implementation for your platform.
And here is `weld-file`, https://github.com/Hywan/weld/compare/7556abeb5d80f015e92634d8b9a6c1494e815b9e...f19d8bae61ef61c443d974bcf3d0a3101a69e7b3.
So far, it supports `std::fs` and `mmap`, more is coming
There is a `FileReader` trait, that reads the content async.