[llvm] [WebAssembly] Handle symbols in `.init_array` sections (PR #119127)

[George Stagg via llvm-commits]

georgestagg wrote:

> I'll let you decide if you want to keep this code.

Now that it's been written, let's keep it. Keeping the objects clean is better.

> Can we split this out into a helper function?

Yes, but I've used a slightly different calling form:

```c
    if (SectionName.starts_with(".init_array") &&
        !isSectionReferenced(Asm, Section))
      continue;
```

The latest version of the commit has the logic in a separate function. If all looks good, could you hit the merge button for me? I don't have write access to the repo.

Also, if you don't mind, would you help me set up the llvmbot so as to request a backport of both #111008 and this PR to the 19.x release branch, please?

Thanks again for taking the time to review and feedback.

https://github.com/llvm/llvm-project/pull/119127