glibc make check fails...

[Roland McGrath]

> This is why the macros in <tls.h> don't use INLINE_SYSCALL.  I should
> have caught this before.  The answer is torewrite the code a bit which
> is trivial.

Yes, just not quite trivial enough for me to do blearily at 5am today. :)

However, this does not explain AJ's crash because he has a build with no
__NR_set_thread_area.  It must be the modify_ldt call failing, for which we
have no explanation and AFAIK noone else has seen it.

In principle the modify_ldt call can fail too, and it would be preferable
to crash in abort as intended rather than crash in the errno access.
Also I would be happier not having the duplication between tls.h and useldt.h.