7351 NVMe driver sporadically lost track of completed I/O request, which
leads to zpool hanging and machine panic.

*** 96,105 ****
--- 96,108 ----
          uint16_t nq_next_cmd;
          uint_t nq_active_cmds;
          int nq_phase;
  
          kmutex_t nq_mutex;
+         hrtime_t nq_ts;
+         list_node_t nq_list_node;
+         nvme_t *nq_nvme;
  };
  
  struct nvme {
          dev_info_t *n_dip;
          int n_progress;
*** 114,123 ****
--- 117,127 ----
          int n_intr_cnt;
          uint_t n_intr_pri;
          int n_intr_cap;
          int n_intr_type;
          int n_intr_types;
+         int n_intr_timeouts;
  
          char *n_product;
          char *n_vendor;
  
          boolean_t n_dead;