Fix some unittests for 64-bit asm. They were operating on int variables as if they were longs. This was causing asm1_1 to fail when compiled with -O3 because it was overwriting the spilled value of callee-saved register %rbx, which the runtime was using as a pointer value at the time.

module multiarr3;

void main()
{
    static int[2][2] arr = [[1,2],[3,4]];
    assert(arr[0][0] == 1);
    assert(arr[0][1] == 2);
    assert(arr[1][0] == 3);
    assert(arr[1][1] == 4);
}