[Bug tree-optimization/66264] [untaken optimization] switch & enums without default-case

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66264

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
enum Foo { A,B,C,D };

int square(Foo f) {
  switch (f) {
    case A: return 33;
    case B: return 24;
    case C: return 857;
    case D: return 980;
    //default: return 0;
  };

  //return 0; // uncomment this to get the fast code
}

Just in case the goo.gl link goes away.