Just a small step along the way to reduce the massive wall of spam
every time you compile.

This was done partly automagically with `cargo fix`. The rest was me
deleting or commenting out a bunch of variables. Hope nothing was
important...

https://github.com/BurntSushi/rust-memchr is supposed to be a whole
lot faster :)

Changed while loops to for - https://gitlab.redox-os.org/redox-os/relibc/issues/128

For AArch64, the ring crate depends on the presence of this header and a definition
of getauxval.

iscntrl: Didn't handle the EOF macro correctly
isgraph: Didn't handle '~' (tilde) correctly
ispunct: Several issues

Implement ttyname by adding fpath function to Sys. Remove realpath function and use fpath internally