Restore missing check for flockfile and getc_unlocked

configure

@@ -15522,6 +15522,22 @@ fi
 done
 
 
+#
+# flockfile is usually provided by pthreads
+#
+for ac_func in flockfile getc_unlocked
+do :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
+  cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+
 #
 # Look for sysconf to allow detection of the number of processors.
 #