[clang] [Clang] Correct handling of negative and out-of-bounds indices (PR #71877)

[Kees Cook via cfe-commits]

https://github.com/kees commented:

For the test cases, I wonder if it might be good to add __bdos() calls with type 0 as well. The results should always be the same, but we do want to check for that. i.e.:

`  p->array[index] = __builtin_dynamic_object_size(&p->count, 0);`


https://github.com/llvm/llvm-project/pull/71877