[disasm] Make jump target printing perf friendly

tools/objdump-v8

 #!/usr/bin/env python
 #
 # Copyright 2016 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 55 matching lines @@
     with codefile:
       printing = False
       for line in codefile:
         if line.startswith("0x"):
           addr = int(line.split()[0], 0)
           if start <= addr <= end:
             printing = True
             sys.stdout.write(format_line(line))
           elif printing:
             break
-        elif printing and not is_comment(line):
-          break
+        elif printing:
+          if not is_comment(line):
+            break
+          else:
+            sys.stdout.write(line)
   else:
     sys.argv[0] = "objdump"
     sys.exit(subprocess.call(sys.argv))
 
 if __name__ == "__main__":
   main()