saveargs: let disasm do the lifting

*** 22,33 ****
  /*
   * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
- #pragma ident   "%Z%%M% %I%     %E% SMI"
- 
  #include <libdisasm.h>
  #include <stdlib.h>
  #include <stdio.h>
  
  #include "dis_tables.h"
--- 22,31 ----
*** 243,247 ****
--- 241,254 ----
  
  done:
          dis_free(hist, sizeof (uint64_t) * n);
          return (res);
  }
+ 
+ int
+ dis_instrlen(dis_handle_t *dhp, uint64_t pc)
+ {
+         if (dis_disassemble(dhp, pc, NULL, 0) != 0)
+                 return (-1);
+ 
+         return (dhp->dh_addr - pc);
+ }