Removed tango from the repository and instead added a runtime dir with the files needed to patch and build tango from svn. Reworked the LLVMDC specific pragmas.

module union1;

union U
{
    float f;
    int i;
}

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