[lld] wasm-ld: Implement function pointer alignment (PR #105532)

[Ethan O'Brien via llvm-commits]

ethanaobrien wrote:

I've created a minimal function to confirm this is something to do with the FILE->write addr. It makes no sense from my perspective why this would affect stdio functions at all, which is why I have no idea where to even begin to debug this.

```C
int get_write_addr(FILE *f)
{
        f->write(f, 0, 0);
        return (int)&f->write;
}
```

<img width="545" height="273" alt="image" src="https://github.com/user-attachments/assets/30105b3b-4863-4f78-806f-ccd6627f488c" />


https://github.com/llvm/llvm-project/pull/105532