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 cond1;

void main()
{
    double a = 2;
    double b = 4;
    double c = (a > 0) ? a : b;
}