I've also added an osv/ prefix to make sure we don't clash with system headers.

We probably should either adopt this globally or drop it, but I fear we'll run into
problems with the latter approach.

Various glibc tests need it.

This is inspired by the FreeBSD code, but nothing but the header and function
names are left of the original version.

Doesn't actually support real asynchronous execution as we're missing the concept
of waitqueues in osv as of now, but that will be added soon.

We want these in line buffered mode, but to get that we need to query the
console driver if it is a tty, and we can only do that after the VFS has
been brought up.

The test code assumes /tests contains shared objects.

This will allow for easy addition of the vectored and positional I/O
syscalls, as well as making the structure of the I/O path more similar
to *BSD and Solaris.

until we support symlinks lxstat is identical to stat

Style requires manual edititing of loader.cc to run, no automated way
to pick up whole directories in the manifest, and we won't clear the
environment before running the next .so

Fix various corner cases to pass the glibc test suite.

Caught by make mode=release.

Since file::file() did not open the file, file::~file() must not free it.

Use ::dup() so we operate on a clone.

Also based on prex code.

Various changes to fit into the OSv environment.  This also includes
a ramfs in-memory full filesystem.  Bootfs is rewritten as a simple
unpacker into ramfs, and the fs class is modified to wrap the VFS
instead of being an abstract subclass.

Usedful for implementing stdio.

Store directory entries in a hash table for future lookup.

We need one object, so we can use it as a key in the cache.  Store it in
the filesystem object.

It interferes with the upcoming cache lookup.  Use the existing metadata
instead to look for a directory.

real filesystems (and /proc, our immediate target) look up files incrementally
by each component.  Apply that to our filesystem infrastructure.

A new object is introduced, dir, representing a directory.  Lookup operations
are deferred to this object.

avoid leakage