Deprecate inclusion of <sys/sysmacros.h> by <sys/types.h>

Deprecate inclusion of <sys/sysmacros.h> by <sys/types.h>

The macros defined by <sys/sysmacros.h> are not part of POSIX nor XSI, and
their names frequently collide with user code; see for instance glibc bug
19239 and Red Hat bug 130601.  <stdlib.h> includes <sys/types.h> under
_GNU_SOURCE, and C++ code presently cannot avoid being compiled under
_GNU_SOURCE, exacerbating the problem.

	* NEWS: Inclusion of <sys/sysmacros.h> by <sys/types.h> is deprecated.
	* misc/sys/sysmacros.h: If __SYSMACROS_DEPRECATED_INCLUSION is defined,
	define major, minor, and makedev to issue deprecation warnings on use.
	If __SYSMACROS_DEPRECATED_INCLUSION is *not* defined, suppress
	previously-activated deprecation warnings for these macros and prevent
	subsequent inclusions of this header from having any effect.
	* posix/sys/types.h: Define __SYSMACROS_DEPRECATED_INCLUSION before
	including <sys/sysmacros.h>, and undefine it again afterward.