Correctly parse `/etc/passwd` and `/etc/group` on Redox

See merge request redox-os/relibc!432

Redox uses `;` as separators in these files, and doesn't have the
"password" flag in `/etc/group`. With these, it seems to parse fine.

Use libc crate correctly, and future-proof

See merge request redox-os/relibc!429

Simplify wcsrtombs and make test follow standard

See merge request redox-os/relibc!428

getline, getdelim: fix issues, extend tests

See merge request redox-os/relibc!418

Make escalated communication pathless using sendfd.

See merge request redox-os/relibc!424

Fix ungetwc for multi byte chars

See merge request redox-os/relibc!425

Add wcpcpy, wcpncpy, wcsdup, wcsnlen, wcsnrtombs

See merge request redox-os/relibc!426

Add UTIME_OMIT and UTIME_NOW

See merge request redox-os/relibc!427

Make fgetwc real multibyte

See merge request redox-os/relibc!423

Implement (not yet the entire) libredox ABI

See merge request redox-os/relibc!419

Use a .flag() with an if statement for mno-outline-atomics

See merge request redox-os/relibc!422

Use flag_if_supported instead of flag for mno-outline-atomics

See merge request redox-os/relibc!421

The x86 build fails due to unknown flag when using just .flag()

Add -mno-outline-atomics when building C code

See merge request redox-os/relibc!420

Fixes building the aarch64 toolchain. Disables emitting
`__aarch64_swp4_sync` and similar functions.

epoll: correct error when skipping time events

See merge request redox-os/relibc!416