Add some alignment info where LLVM might otherwise be more pessimistic. In particular, %.nest_arg is always aligned even though it's bitcast from i8*. Pointers in vtables are also guaranteed to be stored at aligned addresses.

void main()
{
    float m[4][4];

    float* fp = &m[0][0];
    for (int i=0; i<16; i++,fp++)
        assert(*fp !<>= 0);
}