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.

module bug74;

char[] sformat(char[] s, ...)
{
    TypeInfo[] ti = _arguments;
    void* args = _argptr;
    return "";
}

void main()
{
}