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.

void main()
{
    int[4] a = [1,2,3,4];
    int[4] b = [5,6,7,8];
    a[] += b[] / 2;
    assert(a[0] == 3);
    assert(a[1] == 5);
    assert(a[2] == 6);
    assert(a[3] == 8);
}