libc MT-safety, part 2.

Add a lock to FILE.  flockfile and friends are now implemented
(for the most part) in libc.  flockfile_debug is implemented in
libc_r; I suppose it's about time to kill it but will do it in
a future commit.

Fix a potential deadlock in _fwalk in a threaded environment.
A file flag (__SIGN) was added to stdio.h that, when set, tells
_fwalk to ignore it in its walk.  This seemed to be needed in
refill.c because each file needs to be locked when flushing.

Add a stub for pthread_self in libc.  This is needed by flockfile
which is allowed by POSIX to be recursive.

Make fgetpos() error return value (-1) match man page.

Remove recursive calls to locked functions (stdio); I think I've
got them all, but I may have missed a couple.

A few K&R -> ANSI conversions along with removal of a few instances
of "register".

$Id$ -> $FreeBSD$ in libc/stdio/rget.c

Not objected to:	-arch, a few months ago

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/libc/stdio/fgetc.c b/lib/libc/stdio/fgetc.c
index a367af3..684da00 100644
--- a/lib/libc/stdio/fgetc.c
+++ b/lib/libc/stdio/fgetc.c
@@ -46,6 +46,7 @@ static const char rcsid[] =
 #include <stdio.h>
 #include "un-namespace.h"
 #include "libc_private.h"
+#include "local.h"
 
 int
 fgetc(fp)