[Bug c/60121] gcc does not warn an obvious out-of-bound array access at -O0 and -O1

[su at cs dot ucdavis.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60121

--- Comment #1 from Zhendong Su <su at cs dot ucdavis.edu> ---
Here is the testcase: 


-------------------------


int a, b[1];

int
main ()
{
 lbl:
  for (; a; a--)
    if (b[613])
      goto lbl;

  return 0;
}