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 typeinfo;
extern(C) int printf(char*, ...);

void main()
{
    auto ti = typeid(int);
    char[] str = ti.toString();
    printf("%.*s\n", str.length, str.ptr);
    assert(str == "int");
}