[sanitize] Add short-circuit to ArrayOfM1

Like the sibling ArrayOf types.

src/hb-open-type.hh

@@ -861,6 +861,7 @@ struct ArrayOfM1
   {
     TRACE_SANITIZE (this);
     if (unlikely (!sanitize_shallow (c))) return_trace (false);
+    if (!sizeof... (Ts) && hb_is_trivially_copyable (Type)) return_trace (true);
     unsigned int count = lenM1 + 1;
     for (unsigned int i = 0; i < count; i++)
       if (unlikely (!c->dispatch (arrayZ[i], hb_forward<Ts> (ds)...)))