Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

MFC r320472,r320508,r320509:
Make stdio deferred cancel-safe.

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Renumber clauses to reduce diffs to other versions

NetBSD, OpenBSD, and Android's Bionic all number the clauses 1 through 3,
so follow suit to make comparison easier.

Acked-by: imp@

Remove incorrect __restrict qualifier on several pointers

The typical case was:
static __inline int
convert_ccl(FILE *fp, char * __restrict p, [...])
{
[...]

if (p == SUPPRESS_PTR) {
[...]
} else {
[...]
}

[...]
}

This qualifier says that the pointer is the only one at that time
pointing to the resource.

Here, clang considers that "p" will never match "SUPPRESS_PTR" and
optimize the if{} block out. This leads to segfaults in programs calling
vfscanf(3) and vfwscanf(3) with just the format string (no arguments
following it).

The following softwares were reported to abort with segmentation fault
and this patch fixes it:
o cmake
o smartd
o devel/ORBit2

dim@ opened an LLVM PR to discuss this clang optimization:
http://llvm.org/bugs/show_bug.cgi?id=12656

Tested by: bsam@

Fix a bug in *wscanf's handling of non-wide %s, %c, and %[
conversions. Both the specification and the documentation say the
width is interpreted as the max number of wide characters to read, but
the implementation was interpreting it as the number of bytes to convert.
(See also r105317.)

This change has security implications for any applications that depend
on the buggy behavior, but the impact in practice is probably nil.
Any such application would already be buggy on other platforms that
get the semantics right. Also, these conversions are rarely used;
%ls, %lc, and %l[ are more appropriate.

Bugfix: Include whitespace characters in the count of the number of
characters read.

Bugfix: %n doesn't count as a conversion, so
sscanf("abc", "ab%ncd", &i) returns EOF, not 0.

Refactor scanf to improve modularity. Conversions are now performed
by separate conversion functions. This will hopefully make bugs more
noticeable (I noticed several already) and provide opportunities to
reduce code duplication.

Implement xlocale APIs from Darwin, mainly for use by libc++. This adds a
load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.

Please test any code you have that uses the C standard locale functions!

Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)

- Add support for multibyte decimal_point encodings, e.g., U+066B.
A forthcoming gdtoa import is needed to make this fully work.
- Improve the way "nan(...)" is parsed.

Remove some test instrumentation. (The Symbol.map changes broke it anyway.)

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Add missing #if's for NO_FLOATING_POINT

Include <sys/types.h> and <limits.h> ourselves, don't assume they are included
through <pthread.h>.

gen/sem.c: Prerequisite for <_semaphore.h>
net/getprotoent.c: USHRT_MAX
net/getservent.c: USHRT_MAX
stdio/ungetwc.c: MB_LEN_MAX
stdio/vfwscanf.c: MB_LEN_MAX

Remove bogus FBSDID.

Merge vfscanf.c, v1.37:
- s/#ifdef FLOATING_POINT/#ifndef NO_FLOATING_POINT/

Prepare to handle trivial state-dependent encodings. Full support for
state-dependent encodings with locking shifts will come later if there
is demand for it.

Merge vfscanf.c,v 1.35.

Make intentions explicit with additional parenthesis.

Pass NULL instead of a pointer to a zeroed mbstate_t object.

Fix two incorrect uses of sizeof: we need to divide the size of the buffer
by sizeof(wchar_t) to get the number of wide characters it contains.
Remove the !hardway micro-optimisation from the CT_INT case to avoid
having to fix it for wide characters.

Merge recent floating point conversion changes from vfscanf.c.

No need to include floatio.h here: vfscanf() no longer uses anything
it defines.

The field width for single-byte string conversions (%c, %s, %[) is the
maximum number of bytes that may be stored in the array, not the maximum
number of wide characters to read. The wording of the standard unfortunately
does not make this clear.

Remove an unneeded call to _sfrefill() that was missed in the conversion
from vfscanf() to vfwscanf(). It doesn't hurt to have it there, but it's
redundant since __fgetwc() will refill the buffer if it needs to.

Add implementations of wscanf() and related functions: fwscanf(), swscanf(),
vfwscanf(), vswscanf(), vwscanf(). As the name suggests, these are wide-
character versions of the scanf() family of functions.