opEquals needs to return bool

[Steven Schveighoffer]

Because opEquals returns int, this breaks some generic code:

bool isEqual(T)(T t1, T t2)
{
    return t1 == t2;
}

class A
{
}

void main()
{
    int x1 = 5, x2 = 6;
    auto x = isEqual(x1, x2);
    auto c = isEqual("hello", "jello");

    auto a = new A;
    auto ae = isEqual(a, a); // error, cannot convert int to bool
}

Walter, you often say that some ideas can't be implemented because it would 
break generic code, what about this?

-Steve