Use __APPLE_USE_RFC_3542 for darwin.

Some versions of MacOS sdk require this to use the ipv6 socket
options.

Bug: 183216189

Test: Compiles on mac
Change-Id: Id1d484a9f348d465d743128da6cc8c7b7df3d305

1 files changed, 4 insertions, 0 deletions

diff --git a/Android.bp b/Android.bp
index 6dfd7c20..b4566bff 100644
--- a/Android.bp
+++ b/Android.bp
@@ -64,6 +64,10 @@ cc_defaults {
                 "-framework IOKit",
                 "-lobjc",
             ],
+            cflags: [
+                // Required, to use the new IPv6 Sockets options introduced by RFC 3542.
+                "-D__APPLE_USE_RFC_3542",
+            ],
         },
 
         windows: {