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 mini.const1;

void* g = cast(void*)&foobar;

int foobar()
{
    return 42;
}

void main()
{
    auto fn = cast(int function())g;
    int i = fn();
    assert(i == 42);
}