6068 libdisasm: previnstr arch op should have a sane default
Reviewed by: Robert Mustacchi <rm@joyent.com>

*** 195,209 ****
  dis_sparc_min_instrlen(dis_handle_t *dhp)
  {
          return (4);
  }
  
- /*
-  * The dis_i386.c comment for this says it returns the previous instruction,
-  * however, I'm fairly sure it's actually returning the _address_ of the
-  * nth previous instruction.
-  */
  /* ARGSUSED */
  static uint64_t
  dis_sparc_previnstr(dis_handle_t *dhp, uint64_t pc, int n)
  {
          if (n <= 0)
--- 195,204 ----