[Bug sanitizer/81598] -fsanitize=enum does not detect range violation

["marxin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81598

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #4)
> But you get compile-time warnings for that (-Wswitch), no?

For:

cat enum.c
enum values
{
  A = 1000,
  B = 30,
  C = 100
};

int main(int argc, char **argv)
{
  enum values x = (enum values)argc;
  if (x == 12345)
    return 1;

  switch (x)
  {
    case A:
      return 1;
    case B:
      return 1;
    case C:
      return 2;
    case 123:
      return 3;
    default:
      return 4;
  }
}

I only have warning for 'case 123':

gcc -fsanitize=enum enum.c -Wall 
enum.c: In function ‘main’:
enum.c:22:5: warning: case value ‘123’ not in enumerated type ‘enum values’
[-Wswitch]
     case 123:
     ^~~~

But one could also produce warning for the if comparison and default bb in the
switch statement.