10816 ctf_dwarf_convert_type() relies on un-initialized id
10817 ctfconvert -i option is mis-handled
10818 Improve ctfconvert error messages
10819 ctfconvert should handle empty dies
10820 ctfconvert -i never converts
10821 bad free in ctf_dwarf_init_die
10815 shouldn't build gcore.c as part of kmdb
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

*** 22,32 ****
  /*
   * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  /*
!  * Copyright (c) 2015, Joyent, Inc.
   */
  
  #include <ctf_impl.h>
  
  static const char *const _ctf_errlist[] = {
--- 22,32 ----
  /*
   * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  /*
!  * Copyright (c) 2019, Joyent, Inc.
   */
  
  #include <ctf_impl.h>
  
  static const char *const _ctf_errlist[] = {
*** 81,91 ****
          "Label already exists",                          /* ECTF_LABEL */
          "Merged labels conflict",                        /* ECTF_LCONFLICT */
          "Zlib library failure",                          /* ECTF_ZLIB */
          "CTF conversion backend error",                  /* ECTF_CONVBKERR */
          "No C source to convert from",                   /* ECTF_CONVNOCSRC */
!         "No applicable conversion backend"               /* ECTF_NOCONVBKEND */
  };
  
  static const int _ctf_nerr = sizeof (_ctf_errlist) / sizeof (_ctf_errlist[0]);
  
  const char *
--- 81,91 ----
          "Label already exists",                          /* ECTF_LABEL */
          "Merged labels conflict",                        /* ECTF_LCONFLICT */
          "Zlib library failure",                          /* ECTF_ZLIB */
          "CTF conversion backend error",                  /* ECTF_CONVBKERR */
          "No C source to convert from",                   /* ECTF_CONVNOCSRC */
!         "No debug info found to convert from"            /* ECTF_CONVNODEBUG */
  };
  
  static const int _ctf_nerr = sizeof (_ctf_errlist) / sizeof (_ctf_errlist[0]);
  
  const char *