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

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

Rename __wchar_t so it no longer conflicts with __wchar_t from clang 3.4
-fms-extensions.

MFC after: 2 weeks

Correctly expose xlocale functions if people include the headers in the wrong
order (as some ports apparently do).

Approved by: dim (mentor)

Be like stdlib.h and bring in a wchar_t definition and use it to prototype
wcstoimax and wcstoumax, rather than spelling it __wchar_t. This is necessary
to use these functions in C++ where wchar_t is different to __wchar_t and is
a built-in type.

It may be better to use __wchar_t here and to simply define __wchar_t as being
wchar_t in C++ mode rather than to bring in wchar_t, but this is less invasive
and follows our existing practice, and restores wchar_t usage in this file to
what it was before r1.8.

Add the remaining C99 wide character string to integer conversion functions.
Restrict qualifiers were added to the existing prototypes in <inttypes.h>
and the typedef for wchar_t was removed.

Style: One space between "restrict" qualifier and "*".

o Merge <machine/ansi.h> and <machine/types.h> into a new header
called <machine/_types.h>.
o <machine/ansi.h> will continue to live so it can define MD clock
macros, which are only MD because of gratuitous differences between
architectures.
o Change all headers to make use of this. This mainly involves
changing:
#ifdef _BSD_FOO_T_
typedef _BSD_FOO_T_ foo_t;
#undef _BSD_FOO_T_
#endif
to:
#ifndef _FOO_T_DECLARED
typedef __foo_t foo_t;
#define _FOO_T_DECLARED
#endif

Concept by: bde
Reviewed by: jake, obrien

- Add the 'restrict' qualifier to the function prototypes and
definitions of the functions that convert strings to numbers
and are defined by IEEE Std 1003-1.2001.
- Use ANSI-C function definitions for all of the functions
mentioned above plus strtouq and strtoq.
- Update the prototypes in the manual pages.

Don't define wchar_t if we are a C++ compiler.

PR: 31864, 40084

Add support for C++.

Submitted by: bde
PR: 33590

o Implement imaxabs(), imaxdiv(), llabs(), lldiv().
o Update abs(3), div(3), labs(3), ldiv(3) to reflect standards
conformance and add additional references.

Reviewed by: bde, wollman

o Add new header <sys/stdint.h>.
o Make <stdint.h> a symbolic link to <sys/stdint.h>.
o Move most of <sys/inttypes.h> into <sys/stdint.h>, as per C99.
o Remove <sys/inttypes.h>.
o Adjust includes in sys/types.h and boot/efi/include/ia64/efibind.h
to reflect new location of integer types in <sys/stdint.h>.
o Remove previously symbolicly linked <inttypes.h>, instead create a
new file.
o Add MD headers <machine/_inttypes.h> from NetBSD.
o Include <sys/stdint.h> in <inttypes.h>, as required by C99; and
include <machine/_inttypes.h> in <inttypes.h>, to fill in the
remaining requirements for <inttypes.h>.
o Add additional integer types in <machine/ansi.h> and
<machine/limits.h> which are included via <sys/stdint.h>.

Partially obtain from: NetBSD
Tested on: alpha, i386
Discussed on: freebsd-standards@bostonradio.org
Reviewed by: bde, fenner, obrien, wollman