At least in neovim, `│vi:` is not recognized as a modeline because it
has no preceding whitespace. After fixing this, opening a file yields
an error because `net` is not an option. (`noet`, however, is.)
Qemu appears to define O_LARGEFILE as having its x86-64 value, which is
an easy mistake to make since this is one of the few magic numbers that
Linux special-cases for AARCH64.
This change gets GNU grep working. What caused it to not work, is it
wouldn't write to an output file descriptor when its dev/ino equaled
/dev/null's. So now we invent special dev/ino values for these files