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 bug15;

bool bool1(bool b) {
    if (b) return true;
    else return false;
}

bool bool2(bool b) {
    if (b) {return true;}
    else {return false;}
}

void main()
{
    assert(bool1(true));
    assert(!bool2(false));
}