[clang] [analyzer] Fix crash in Stream checker when using void pointers (PR #97199)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat approved this pull request.

Thanks for the updates! I added few minor comments, but the PR is already good enough to be merged.

> >  I only noticed that this PR was already merged after posting the review. There is no need to revert the commit -- it's better than nothing -- but I'd be happy if you created a followup change that also handles the testcase that I mentioned.
>
> I'm not sure what you refer to. This PR is not approved, hence not merged. Please continue with the review.

Oops, sorry -- I was probably confused by the purple "merged" icon in 
![image](https://github.com/llvm/llvm-project/assets/43410265/e4b494d4-014f-4b03-942b-00debb90a709)
...but the real reason is that I got up at 4 AM today :sleeping: 


https://github.com/llvm/llvm-project/pull/97199