When encoding fails in fputwc(3), set the error indicator as required
by POSIX and as FreeBSD, SunOS 10/11, and glibc also do it. Note
that an enquiry to the Austin Group led to the conclusion that this
change probably violates the C standard: C and POSIX unintentionally
conflict. But the POSIX behaviour makes more sense (easier to write
correct error handling code for it, and a lower risk that programs
miss errors) and is much more widespread, and the Austin Group
intends to approach the C committee in order to adjust the C standard.
See: http://austingroupbugs.net/view.php?id=1022

While here, do not set errno a second time, wcrtomb(3) already did that,
and it is required to do it by the standard.

OK millert@ and tedu@, and jca@ no longer objects

Eliminate the last of the LINTEDn and PRINTFLIKEn comments. In one
case, by deleting some useless '& of an array' we also eliminate the need
for the casts which prompted the original lint warnings

ok deraadt@

Add framework for resolving (pun intended) libc namespace issues, using
wrapper .h files and asm labels to let internal calls resolve directly and
not be overridable or use the PLT. Then, apply that framework to most of
the functions in stdio.h, string.h, err.h, and wchar.h. Delete the
should-have-been-hidden-all-along _v?(err|warn)[cx]? symbols while here.

tests clean on i386, amd64, sparc64, powerpc, and mips64

naming feedback from kettenis@ and millert@
ok kettenis@

Fix the handle locking in stdio to use flockfile/funlockfile
internally when and where required. Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking. A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization. Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

committing on behalf of and okay guenther@ now that we have install
media space available.

Back out previous commit, as it caused too much growth for the install
media to fit

Fix the handle locking in stdio to use flockfile/funlockfile
internally when and where required. Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking. A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization. Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.

ok kurt@, earlier version tested by sthen@ and jj@

next citrus step.

reviewed by millert, otto, kevlo, naddy, kettenis...
libc+libstdc++ bump