* sysdeps/unix/sysv/linux/powerpc/bits/stat.h: Define UTIME_NOW and

* sysdeps/unix/sysv/linux/powerpc/bits/stat.h: Define UTIME_NOW and

	UTIME_OMIT.
	* sysdeps/unix/sysv/linux/x86_64/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/s390/bits/stat.h: Likewise.
	* sysdeps/unix/sysv/linux/kernel-features.h: Define __ASSUME_UTIMENSAT.
	* io/sys/stat.h: Declare utimensat, futimens.
	* io/utimensat.c: New file.
	* io/futimens.c: New file.
	* sysdeps/unix/sysv/linux/utimensat.c: New file.
	* sysdeps/unix/sysv/linux/futimens.c: New file.
	* io/Makefile (routines): Add utimensat, futimens.
	* io/Versions: Add utimensat, futimens to GLIBC_2.6.
	* sysdeps/unix/sysv/linux/lutimes.c: New file.
	* sysdeps/unix/sysv/linux/futimes.c: Use utimensat syscall if
	available.

	* include/sys/cdefs.h: Redefine __nonnull so that test for
	incorrect parameters in the libc code itself are not omitted.