RS: add assert that checks listen wen vec to be onehot

src/main/scala/xiangshan/backend/issue/ReservationStationNew.scala

@@ -331,6 +331,7 @@ class RSDataSingleSrc(srcLen: Int, numEntries: Int, numListen: Int) extends XSMo
   for (i <- 0 until numEntries) {
     when (Cat(wen(i)).orR) {
       value(i) := ParallelMux(wen(i) zip data)
+      assert(RegNext(PopCount(wen(i))===0.U || PopCount(wen(i))===1.U), s"${i}")
     }
   }