glibc make check fails...

[Roland McGrath]

Ok, I was wrong.  I actually can only reproduce this in a build that's
using not 2.4.18 headers but newer headers that define __NR_set_thread_area
(when running on a 2.4.18 kernel that doesn't have the system call).

If that is your situation too, are you sure it worked before?  If that is
not your situation, then I can't reproduce your situation and you will have
to find some more information for me.

The crash I see is from the useldt.h macros' use of INLINE_SYSCALL
resulting in it calling __errno_location, which bombs when %gs isn't set up
yet.  AFAICT the useldt.h macros have the very same issue with errno not
being set up as the TLS macros have (errno TLS var vs __errno_location
definition from libpthread, but both need %gs to be set up or they crash).
So I am going to consolidate those macros and use the versions that avoid
trying to set errno for both.