11626 introduce /etc/versions/build
11627 clean up UUID code for ::status

*** 18,28 ****
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright 2017 Joyent, Inc.
   */
  
  /*
   * Mdb kernel support module.  This module is loaded automatically when the
   * kvm target is initialized.  Any global functions declared here are exported
--- 18,28 ----
   *
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
!  * Copyright 2019 Joyent, Inc.
   */
  
  /*
   * Mdb kernel support module.  This module is loaded automatically when the
   * kvm target is initialized.  Any global functions declared here are exported
*** 1807,1812 ****
--- 1807,1828 ----
                  mdb_warn("failed to read 'nsec_per_tick'");
                  return (-1);
          }
  
          return ((ts/nsec) - lbi.lbi_debug_time);
+ }
+ 
+ void
+ mdb_print_buildversion(void)
+ {
+         GElf_Sym sym;
+ 
+         if (mdb_lookup_by_name("buildversion", &sym) != 0)
+                 return;
+ 
+         char *str = mdb_zalloc(4096, UM_SLEEP | UM_GC);
+ 
+         if (mdb_readstr(str, 4096, sym.st_value) < 1)
+                 return;
+ 
+         mdb_printf("build version: %s\n", str);
  }