PATCH: Add x32 dummy sysctl

[Roland McGrath]

> 	* sysdeps/unix/sysv/linux/Makefile: Include
> 	$(firstword $(wildcard $(sysdirs:=/sysctl.mk))).
> 	(sysdep_routines): Replace sysctl with $(sysctl).
> 
> 	* sysdeps/unix/sysv/linux/sysctl.mk: New file.
> 	* sysdeps/unix/sysv/linux/x86_64/sys/sysctl.h: Likewise.
> 	* sysdeps/unix/sysv/linux/x86_64/x32/sysctl.mk: Likewise.

No blank line between these.

> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86_64/sys/sysctl.h

Don't duplicate the whole file.  Instead split out a bits/sysctl.h,
whose generic (i.e. sysdeps/unix/sysv/linux) version could be empty
except for boilerplate.


Thanks,
Roland