'RELENG_4_0_0_RELEASE'.

This commit was manufactured to restore the state of the 4.0-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

just use _foo() <-- foo().  In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate.  In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().

Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().

Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().

Make thread cancellation fully POSIX-compliant.

Suggested by:	deischen

points.  For library functions, the pattern is __sleep() <--
_libc_sleep() <-- sleep().  The arrows represent weak aliases.  For
system calls, the pattern is _read() <-- _libc_read() <-- read().

as root.  This could fix the "filesystem still dirty after fsck" problem.

Submitted by:   bde

is actually mounted on "/" can be determined using statfs() and is
in /dev.  This fixes fsck operating on the wrong device when the
fs_spec entry is only an alias.  The aliased case became more
dangerous when the ROOTSLICE_HUNT hack was committed in mount(8).
ROOTSLICE_HUNT may be unnecessary now.

if user program use it too in the same time.

Also be more tolerant of blank lines and comments in the file.
Submitted by:	jkh