RECS0135 not firing in recusive converter

[shmuelie]

If you create a converter operator that has infinite recursion RECS0135 does not fire since it isn't a method call in the C#.

class A
{
    public static implicit operator int(A a) => a; // Should show RECS0135 but does not.
}

[Rpinski]

Not exactly the same, but related: #257.