updated for version 7.4.062
Problem:    Configure check for AvailabilityMacros.h is wrong.
Solution:   Use AC_CHECK_HEADERS().
diff --git a/src/auto/configure b/src/auto/configure
index 75f76a6..bb079f0 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -4263,11 +4263,17 @@
 $as_echo "no" >&6; }
 fi
 
-ac_fn_c_check_header_mongrel "$LINENO" "AvailabilityMacros.h" "ac_cv_header_AvailabilityMacros_h" "$ac_includes_default"
+for ac_header in AvailabilityMacros.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "AvailabilityMacros.h" "ac_cv_header_AvailabilityMacros_h" "$ac_includes_default"
 if test "x$ac_cv_header_AvailabilityMacros_h" = x""yes; then :
-  HAVE_AVAILABILITYMACROS_H=1
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_AVAILABILITYMACROS_H 1
+_ACEOF
+
 fi
 
+done