Update dependencies for rust 2022-03-18.

See merge request redox-os/relibc!342

Initialize TLS manually on Redox as Linux does.

See merge request !340

wctype

See merge request !339

Update toolchain

See merge request !338

This also replaces all the assembly that previously used the AT&T style
with the (in my opinion) superior Intel syntax.

I tried prepending `.att_syntax prefix`, but that did not work...