[Nickle] Bug: reference addition bounds check on arrays

[Bart Massey]

I *think* this was supposed to work.

    $ nickle
    > int[3] a;
    > *(int[*]) ar = &a;
    > *(int[*]) ar = &a + 1;
    Unhandled exception invalid_array_bounds ("Element out of range in reference addition", &(int [3]) {<uninit>,<uninit>, <uninit>}, 1)
    <stdin>:3:     *int[*] ar = &a + 1;
    >

I'll look at this bug, but if someone beats me to it...

This is the last thing keeping LOL from working.  I will
implement some slightly icky workaround for now.

	Bart