LWP failed to wake up threads sleeping in empth_sleep() while other

threads were runnable.  This let players with a sufficiently fast
connection starve out system threads, including the update.  Fix:
[EMPTH_LWP] (lwpWakeupSleep): External linkage.
[EMPTH_LWP] (lwpReschedule): Call it.

src/lib/lwp/sel.c

@@ -123,7 +123,7 @@ lwpWakeupFd(struct lwpProc *proc)
     lwpReady(proc);
 }
 
-static void
+void
 lwpWakeupSleep(void)
 {
     time_t now;