Fix a regression in glibc 2.27 when built without ldconfig.  See
<https://sourceware.org/bugzilla/show_bug.cgi?id=22977> for details.

diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index 6137304b0b..7d630f36d8 100644
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -508,7 +508,7 @@ for linking")
 # ifndef __ASSEMBLER__
 #  if !defined SHARED && IS_IN (libc) && !defined LIBC_NONSHARED \
       && (!defined PIC || !defined NO_HIDDEN_EXTERN_FUNC_IN_PIE) \
-      && !defined NO_HIDDEN
+      && !defined NO_HIDDEN && defined USE_LDCONFIG
 #   define __hidden_proto_hiddenattr(attrs...) \
   __attribute__ ((visibility ("hidden"), ##attrs))
 #   define hidden_proto(name, attrs...) \
rm.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
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<div class='path'>path: <a href='/guix/log/?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00'>root</a>/<a href='/guix/log/gnu?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00'>gnu</a>/<a href='/guix/log/gnu/installer?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00'>installer</a>/<a href='/guix/log/gnu/installer/newt?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00'>newt</a>/<a href='/guix/log/gnu/installer/newt/ethernet.scm?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00'>ethernet.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/installer/newt/ethernet.scm?id=33783d9009cb6f5b9cfa433822037e28ca9c9a00&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-11-07 13:19:25 +0100'>2020-11-07</span></td><td><a href='/guix/commit/gnu/installer/newt/ethernet.scm?id=8338d414b361e4fb961221642c1064e9dc89ba65'>installer: Limit listbox height.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes: &lt;https://issues.guix.gnu.org/44428&gt;.

* gnu/installer/newt.scm (init): Print screen size.
* gnu/installer/newt/page.scm (default-listbox-height): New variable.
(run-listbox-selection-page): Use it.
* gnu/installer/newt/wifi.scm (wifi-listbox-height): Ditto.
* gnu/installer/newt/network.scm (run-technology-page): Set the maximum
listbox height to 5.
* gnu/installer/newt/ethernet.scm (run-ethernet-page): Ditto.
* gnu/installer/newt/final.scm (run-config-display-page): Change listbox
height.
* gnu/installer/newt/partition.scm (run-disk-page): Ditto.
* gnu/installer/newt/welcome.scm (display-logo?): New procedure.
(run-menu-page): Use it.
* gnu/installer/steps.scm (%configuration-file-width): Remove it.
</span></span></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2019-05-06 23:21:33 +0200'>2019-05-06</span></td><td><a href='/guix/commit/gnu/installer/newt/ethernet.scm?id=46c102ca5e76ffc1daa42edba439eee9fd0f102c'>installer: Skip network selection dialogs when there is no choice.</a><span class='msg-avail'>...<span class='msg-tooltip'>Previously, for a machine that only has wired networking, and only one
such network, we'd have to go through two selection boxes.  Now we just
skip both.

* gnu/installer/newt/ethernet.scm (run-ethernet-page): When
'ethernet-services' returns one element, return it directly without
opening a listbox selection.
* gnu/installer/newt/network.scm (run-technology-page): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-05-06 23:21:33 +0200'>2019-05-06</span></td><td><a href='/guix/commit/gnu/installer/newt/ethernet.scm?id=d1e5f758e128a3c1042c98563c5b87b81b2f187a'>installer: Shrink simple listboxes to their minimum height.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/installer/newt/partition.scm (run-partioning-page): Pass
 #:listbox-height.
(run-scheme-page): Likewise.
(run-device-page): Likewise.
* gnu/installer/newt/network.scm (run-technology-page): Likewise.
* gnu/installer/newt/ethernet.scm (run-ethernet-page): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>