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.

extern(C) int printf(char*, ...);
void main()
{
    void* i;
    asm
    {
        mov EAX, FS:4;
        mov i, EAX;
    }
    printf("FS:4 = %p\n", i);
}