Fix compile issue for iOS (#717)

src/std/thread.c

@@ -970,7 +970,7 @@ HL_PRIM void hl_thread_set_name( hl_thread *t, const char *name ) {
 	// nothing
 #elif defined(HL_WIN)
 	SetThreadName((DWORD)(int_val)t,name);
-#elif defined(HL_MAC)
+#elif defined(HL_MAC) || defined(HL_IOS)
 	// pthread_setname_np only possible for current thread
 #else
 	pthread_setname_np((pthread_t)t,name);