12364 mdb trips assertion related to autowrap

*** 22,32 ****
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  /*
!  * Copyright 2017 Joyent, Inc.
   */
  
  /*
   * Support for ::set dcmd.  The +/-o option processing code is provided in a
   * stand-alone function so it can be used by the command-line option processing
--- 22,32 ----
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  /*
!  * Copyright 2020 Joyent, Inc.
   */
  
  /*
   * Support for ::set dcmd.  The +/-o option processing code is provided in a
   * stand-alone function so it can be used by the command-line option processing
*** 273,283 ****
          /*
           * The ::set output implicitly relies on "autowrap" being enabled, so
           * we enable it for the duration of the command.
           */
          oflags = mdb.m_flags;
!         mdb.m_flags |= MDB_FL_AUTOWRAP;
  
          mdb_printf("follow_exec_mode=");
          switch (mdb.m_execmode) {
          case MDB_EM_ASK:
                  mdb_printf("ask");
--- 273,283 ----
          /*
           * The ::set output implicitly relies on "autowrap" being enabled, so
           * we enable it for the duration of the command.
           */
          oflags = mdb.m_flags;
!         mdb_iob_set_autowrap(mdb.m_out);
  
          mdb_printf("follow_exec_mode=");
          switch (mdb.m_execmode) {
          case MDB_EM_ASK:
                  mdb_printf("ask");