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...) \
<form method='get'>
<input type='hidden' name='id' value='60c0b4fe97192617a753a9f39b89ecb166405de9'/><select name='h' onchange='this.form.submit();'>
<option value='build-sys'>build-sys</option>
<option value='jahoti'>jahoti</option>
<option value='jahoti-update'>jahoti-update</option>
<option value='koszko'>koszko</option>
<option value='master' selected='selected'>master</option>
<option value='nick'>nick</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>A Web Extension to facilitate replacing sites' js with user-supplied scripts</td><td class='sub right'>