[discuss] Replace libc with relibc

[VitalyAnkh]

It seems that zCore depends on a prebuilt libc.so library. How about replacing libc with relibc, a libc written in pure Rust?

If this is approved, I will try to implement it.

[wangrunji0408]

Now rCore / zCore only supports musl libc, considering it is simple, clear and widely used.
The libc.so is a prebuilt version of musl libc, with all syscall instructions being modified to function calls for libos.

I'm glad to see a pure Rust libc. But it may be an option, not a replacement.
Anyway this is a good idea. You can have a try!