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 bug79;
import std.c.linux.linux;
void main()
{
    timespec ts; 
    ts.tv_nsec -= 1;
    //auto t = ts.tv_nsec - 1;
    //t -= 1;
}