Complete _BSD_SOURCE / _SVID_source followup cleanup.

This patch completes the headers cleanup consequent on removal of
_BSD_SOURCE and _SVID_SOURCE (apart from any subsequent deprecations):

* #endif conditionals that referred to BSD or SVID are updated.

* Redundant __USE_* tests in cases involving __USE_MISC are removed.
  This includes cases such as __USE_MISC || __USE_ISOC99, where
  __USE_MISC is redundant (because __USE_MISC is only ever defined in
  the default / _DEFAULT_SOURCE / _GNU_SOURCE case, when __USE_ISOC99
  is also defined; the same applies to the non-XSI-extended POSIX
  versions), and cases involving __USE_GNU, where __USE_GNU is
  redundant (because if __USE_GNU is defined, so are the other __USE_*
  macros).  There may well be other cases of __USE_FOO || __USE_BAR
  tests that could be simplified because one macro implies the other;
  this patch only addresses cases involving __USE_MISC.

Tested x86_64.

	* bits/fcntl.h [__USE_MISC]: Remove redundant conditionals.
	* bits/sigaction.h [__USE_MISC]: Likewise.
	* bits/waitstatus.h: Update #endif comments.
	* ctype/ctype.h: Likewise.
	* dirent/dirent.h: Likewise.
	[__USE_MISC]: Remove redundant conditionals.
	* grp/grp.h: Update #endif comments.
	[__USE_GNU]: Remove redundant conditionals.
	[__USE_MISC]: Likewise.
	* inet/netinet/in.h [__USE_GNU]: Likewise.
	* io/sys/stat.h [__USE_MISC]: Likewise.
	* libio/bits/stdio-ldbl.h [__USE_MISC]: Likewise.
	* libio/bits/stdio.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* libio/bits/stdio2.h [__USE_MISC]: Likewise.
	* libio/stdio.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* math/bits/math-finite.h [__USE_MISC]: Likewise.
	* math/bits/mathcalls.h [__USE_MISC]: Likewise.
	* math/math.h: Update #else and #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* misc/sys/uio.h: Update #endif comments.
	* posix/bits/unistd.h [__USE_MISC]: Remove redundant conditionals.
	* posix/glob.h [__USE_MISC]: Likewise.
	* posix/sys/types.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* posix/sys/wait.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* posix/unistd.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* pwd/pwd.h [__USE_GNU]: Likewise.
	[__USE_MISC]: Likewise.
	* resolv/netdb.h [__USE_GNU]: Likewise.
	* signal/signal.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* stdlib/stdlib.h: Update #else and #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	[__USE_GNU]: Likewise.
	* string/bits/string2.h [__USE_MISC]: Likewise.
	* string/string.h: Update #endif comments.
	[__USE_MISC]: Remove redundant conditionals.
	* sysdeps/m68k/m680x0/fpu/bits/mathinline.h [__USE_MISC]:
	Likewise.
	* sysdeps/mach/hurd/bits/fcntl.h [__USE_MISC]: Likewise.
	* sysdeps/mach/hurd/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/sigaction.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/stat.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/bits/fcntl-linux.h: Update #endif
	comments.
	[__USE_MISC]: Remove redundant conditionals.
	* sysdeps/unix/sysv/linux/bits/in.h [__USE_GNU]: Likewise.
	* sysdeps/unix/sysv/linux/bits/sigaction.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/bits/socket.h [__USE_GNU]: Likewise.
	* sysdeps/unix/sysv/linux/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/sigaction.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/sigaction.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/stat.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/bits/sigaction.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/s390/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/sigaction.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/stat.h [__USE_MISC]:
	Likewise.
	* sysdeps/unix/sysv/linux/x86/bits/stat.h [__USE_MISC]: Likewise.
	* sysdeps/x86/bits/string.h: Update #endif comments.
	* sysdeps/x86/fpu/bits/mathinline.h [__USE_MISC]: Remove redundant
	conditionals.
	* time/sys/time.h: Update #endif comments.
	* time/time.h: Likewise.
	[__USE_MISC]: Remove redundant conditionals.

sysdeps/unix/sysv/linux/bits/stat.h

@@ -62,7 +62,7 @@ struct stat
 #else
     __blkcnt64_t st_blocks;		/* Number 512-byte blocks allocated. */
 #endif
-#if defined __USE_MISC || defined __USE_XOPEN2K8
+#ifdef __USE_XOPEN2K8
     /* Nanosecond resolution timestamps are stored in a format
        equivalent to 'struct timespec'.  This is the type used
        whenever possible but the Unix namespace rules do not allow the
@@ -108,7 +108,7 @@ struct stat64
     __blksize_t st_blksize;		/* Optimal block size for I/O.  */
 
     __blkcnt64_t st_blocks;		/* Number 512-byte blocks allocated. */
-# if defined __USE_MISC || defined __USE_XOPEN2K8
+# ifdef __USE_XOPEN2K8
     /* Nanosecond resolution timestamps are stored in a format
        equivalent to 'struct timespec'.  This is the type used
        whenever possible but the Unix namespace rules do not allow the