patch-xopen-source-ios.patch

diff --git a/configure.ac b/configure.ac
index cc69015b10..e7fde9c027 100644
--- a/configure.ac
+++ b/configure.ac
@@ -521,6 +521,12 @@ case $ac_sys_system/$ac_sys_release in
     define_xopen_source=no;;
   Darwin/@<:@[12]@:>@@<:@0-9@:>@.*)
     define_xopen_source=no;;
+  iOS/*)
+    define_xopen_source=no;;
+  tvOS/*)
+    define_xopen_source=no;;
+  watchOS/*)
+    define_xopen_source=no;;
   # On QNX 6.3.2, defining _XOPEN_SOURCE prevents netdb.h from
   # defining NI_NUMERICHOST.
   QNX/6.3.2)