Make dill_happyeyeballs_connect() public.

Author: jppunnett

libdill.h

@@ -1090,7 +1090,10 @@ DILL_EXPORT int dill_term_detach(
 /* Implements concurrent TCP connecting to the remote endpoint.               */
 /******************************************************************************/
 
-int dill_happyeyeballs_connect(const char *name, int port, int64_t deadline);
+DILL_EXPORT int dill_happyeyeballs_connect(
+    const char *name,
+    int port,
+    int64_t deadline);
 
 #if !defined DILL_DISABLE_RAW_NAMES
 #define happyeyeballs_connect dill_happyeyeballs_connect