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.)
- Use good ELF technique in cosmo_dlopen()
- Make strerror() conform more to other libc impls
- Introduce __clear_cache() and use it in cosmo_dlopen()
- Remove libc/fmt/fmt.h header (trying to kill off LIBC_FMT)
This lets our system() and popen() commands function sort of like
BusyBox and ToyBox. By default the Cosmopolitan Shell is lightweight.
But if you use STATIC_YOINK then you can pull the individual commands
you want into the linkage, and they'll be included in a single binary.
For example the demo binary embeds `tr` and `sed` and ends up ~140kb.