Feature request, move part of std::io into core::io to be used by rust-libc such as relibc

[lygstate]

Get std::io to be an core::io component so that can be used by runtime implemenation.

Especially for posix libc implemenation in rust with

• syscall(Linux)
• win32 api (windows)
• syscall(osx)
• syscall(redox)
• ? (fedora)
  and so on.

This is for https://github.com/redox-os/relibc

Also for
https://github.com/rulibc/rulibc
The fork of relibc that act as an msvcrt/mingw/cygwin/msys2 alternative on win32

glibc/musl alternative on linux world.

redox support will alomost unchanged with the upstream Thttps://github.com/redox-os/relibc

And makes platform dependent IoSliceMut can be customized by the user
And give the default impl for windows/posix.

#36193
related

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[clarfonthey]

This has been brought up before a lot of times and I'm for moving a decent chunk of std::io (at least traits) into core::io, but I think that we'd want an RFC to hash out the details.

[lygstate]

This has been brought up before a lot of times and I'm for moving a decent chunk of std::io (at least traits) into core::io, but I think that we'd want an RFC to hash out the details.

Thanks, I actually didn't move std::io to core::io yet, Just post a list of files that affect when I used them to implement posix c runtime.

[mati865]

There was an RFC: rust-lang/rfcs#2262
Main blocker: rust-lang-nursery/portability-wg#12

[bors]

☔ The latest upstream changes (presumably #78001) made this pull request unmergeable. Please resolve the merge conflicts.

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[lygstate]

use #77922 instead