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.)
This change fixes Cosmopolitan so it has fewer opinions about compiler
warnings. The whole repository had to be cleaned up to be buildable in
-Werror -Wall mode. This lets us benefit from things like strict const
checking. Some actual bugs might have been caught too.
lz4toasm should now more easily accept LZ4 files output by
compressor programs that do not support the extracted-size
field, such as Stephan Brumme's smallz4.
This patch also proposes to add a new lz4len() function to
the libc: it parses an LZ4 compressed block to compute the
unpacked content size, without really unpacking the block.
Co-authored-by: tkchia <tkchia-cosmo@gmx.com>