This patch changes the NBSD libc stat implemenation and adds
fstat (and headers), taken from current libc.
It also adds weaks alias to functions in the resolver that
were removed from public use in NetBSD but that are still
used by Minix, and fixes a NetBSD non-REENTRANT bug in
in gen/initdir.c.
This patch mainly copies and modifies files existing in
the current libc implementing minix specific functions.
To keep consisten with the NetBSD libc, we remove
namespace stubs and we use "namespace.h" and weak
links.
