RFC: Remove --disable-hidden-plt

[H.J. Lu]

--disable-hidden-plt was added by

commit 749a9a4fbfd261e2d9811d9bc4507478c2f7cc58
Author: Roland McGrath <roland@gnu.org>
Date:   Tue Oct 1 08:45:44 2002 +0000

    2002-10-01  Roland McGrath  <roland@frob.com>

            * config.h.in (NO_HIDDEN): New #undef.
            * include/libc-symbols.h [! NO_HIDDEN]: Add this condition to
            nonempty definitions of hidden_proto et al.
            * configure.in: Grok --disable-hidden-plt to define NO_HIDDEN.
            * configure: Regenerated.
            * sysdeps/mach/hurd/configure.in: Always define NO_HIDDEN.
            * sysdeps/mach/hurd/configure: Regenerated.

It doesn't work on x86-64:

https://sourceware.org/bugzilla/show_bug.cgi?id=27692

Should it be removed?

-- 
H.J.