[clang] [analyzer] Hotfix a boolean conversion crash in the Z3 SMTConv (PR #158276)

[Balazs Benics via cfe-commits]

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

Following this thread gave me a sense of urgency.
I'll admit, it took me much longer to write this comment than doing the review.

I think the patch looks okay, given the circumstances. I'd only highlight here that I think using the argument that anything is better than having a crash - while is true, still leaves a bitter taste.
I have not counted how many similar crashes we had within the Z3 conversion layer, but I still stand by what I've said, that we need to investigate these and put an end to this.
I'll also acknowledge the fact that probably its just a personal  bias that @vabridgers, you, happen to stand guard at your fuzzer target/bot (or real user reports) and not only report but also propose quickfixes to the found issues.
I deeply appreciate that.

https://github.com/llvm/llvm-project/pull/158276