native build (WIP)

[hasanalrasyid]

Thank you for this invaluable piece.
In my use case, the existence of Relude is a must to make more common codes between server-side code (built in native compilation) and client-code (melange).

This contribution and pull request is a WIP. It tried to make compilation of Relude is possible in native environment.
Most of the work was done by exchanging Belt modules with comparable modules in JaneStreet Base/Core or straight from OCaml default libraries, with the latter should be the priority. Hopefully, we can reduce it to single dependency.
There are several modules that not yet to be handled, namely Js, IO (related with async), etc.
The tests also not yet polished for native, so we need to use it with a grain of salt.
Nonetheless, most parts are compiled and should be usable.

The progress would be shown in the native branch.

Regards,
Hasan