finish lab1 with some fix.

1. finished lab 1
2. fix a god-I-don't-know-stabs-bug in kdebug, by manually mark some
N_FUN stats entry INVAILD.
   see exactly what going on in stabs file,
   there are some lines like this:
   106    FUN    0      0      00000060 0
   which is make nosense at all and the target line
   should be
   96     FUN    0      12     f0100040 2835   test_backtrace:F(0,18)
   so i Mark lines like #106 INVAILD. which is can not be search by
   stab_binsearch.

Signed-off-by: sunus <sunuslee@gmail.com>
Merge branch 'lab1'
ready to push to github.