Change the numbering of static ctors/dtors to be module based instead of being global. This fixes #210 by making sure that the static ctor always gets the same number, regardless of the order of the modules given at the command line.

module union1;

union U
{
    float f;
    int i;
}

void main()
{
    float f = 2;
    U u = U(f);
    assert(u.i == *cast(int*)&f);
}