[Bug tree-optimization/83957] ICE: Segmentation fault (in gimple_phi_arg)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83957

--- Comment #1 from Arseny Solokha <asolokha at gmx dot com> ---
Actually, the testcase can be reduced to just

void
k2 (int *ch, int fw)
{
  if (fw < 0)
    while (fw < 1)
      {
        ch = &fw;
        ++fw;
      }
}