mknod: new module Solaris 9 mknod("name/",mode,dev) mistakenly creates "name" for non-directory mode. FreeBSD 7.2 mknod("dangling/",mode,dev) mistakenly creates the target of the symlink if run as root. FreeBSD and OpenBSD mknod("fifo",S_IFIFO|mode,0) fails for non-root. Use of mknod caused link failures on mingw. * modules/mknod: New file. * m4/mknod.m4 (gl_FUNC_MKNOD): Likewise. * lib/mknod.c (mknod): Likewise. * m4/sys_stat_h.m4 (gl_SYS_STAT_H_DEFAULTS): Set witness defaults. * modules/sys_stat (Makefile.am): Substitute them. * lib/sys_stat.in.h (mknod): Declare replacement. * MODULES.html.sh (Support for systems lacking POSIX:2008): Document it. * doc/posix-functions/mknod.texi (mknod): Likewise. * modules/mknod-tests: New test. * tests/test-mknod.c: Likewise. Signed-off-by: Eric Blake <ebb9@byu.net>