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...) \
on value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>refs</a><a class='active' href='/guix/log/gnu/packages/adns.scm'>log</a><a href='/guix/tree/gnu/packages/adns.scm?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>tree</a><a href='/guix/commit/gnu/packages/adns.scm?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>commit</a><a href='/guix/diff/gnu/packages/adns.scm?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/adns.scm'>
<input type='hidden' name='id' value='3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>root</a>/<a href='/guix/log/gnu?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>gnu</a>/<a href='/guix/log/gnu/packages?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>packages</a>/<a href='/guix/log/gnu/packages/adns.scm?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3'>adns.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/packages/adns.scm?id=3f62ddc0d5eebbff32bd05ba42148fdc3a6b02e3&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-12-13 17:48:25 +0100'>2021-12-13</span></td><td><a href='/guix/commit/gnu/packages/adns.scm?id=8394619baceb118df92e355377fd543bb1aa501a'>gnu: Simplify package inputs.</a><span class='msg-avail'>...<span class='msg-tooltip'>This commit was obtained by running:

  ./pre-inst-env guix style

without any additional argument.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-11-17 23:43:14 +0100'>2021-11-17</span></td><td><a href='/guix/commit/gnu/packages/adns.scm?id=3a317f7476f8c6012e166ff9f340f861938721c9'>Merge branch 'master' into core-updates-frozen</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-11-15 22:43:23 +0100'>2021-11-15</span></td><td><a href='/guix/commit/gnu/packages/adns.scm?id=ecbf59abad4e146a80ea2849d12569886bce732e'>gnu: Add c-ares-for-node.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/adns.scm (c-ares-for-node): New variable.

Co-authored-by: Marius Bakke &lt;marius@gnu.org&gt;
</span></span></td><td>Jelle Licht</td></tr>
<tr><td><span title='2021-10-18 14:37:26 +0000'>2021-10-18</span></td><td><a href='/guix/commit/gnu/packages/adns.scm?id=e486b2b674badc80627b11077b7df2ac1cab92d8'>Merge remote-tracking branch 'signed/master' into core-updates</a></td><td>Mathieu Othacehe</td></tr>
<tr><td><span title='2021-10-17 02:27:16 +0200'>2021-10-17</span></td><td><a href='/guix/commit/gnu/packages/adns.scm?id=a1030d215197148aa0b86b75edccb70884c3769f'>gnu: c-ares: Update to 1.17.2.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/adns.scm (c-ares/fixed): Update to 1.17.2.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>