1730 DTrace should ignore type information from modules with cth_parlabel mismatches
Reviewed by: Keith Wesolowski <keith.wesolowski@joyent.com>
Reviewed by: Adam Leventhal <ahl@delphix.com>

*** 978,987 ****
--- 978,997 ----
  {
          return (fp->ctf_parname);
  }
  
  /*
+  * Return the label of the parent CTF container, if one exists.  Otherwise
+  * return NULL.
+  */
+ const char *
+ ctf_parent_label(ctf_file_t *fp)
+ {
+         return (fp->ctf_parlabel);
+ }
+ 
+ /*
   * Import the types from the specified parent container by storing a pointer
   * to it in ctf_parent and incrementing its reference count.  Only one parent
   * is allowed: if a parent already exists, it is replaced by the new parent.
   */
  int