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 bug25;
extern(C) int printf(char*, ...);

void main()
{
    int i = 2;
    delegate {
        i = i*i;
        i += i*i;
    }();
    printf("%d\n", i);
    assert(i == 20);
}