[clang] [clang] Fix the post-filtering heuristic for GSLPointer. (PR #114044)

[Haojian Wu via cfe-commits]

hokein wrote:

Figured out a way to fix the false positives while not introducing many false negatives. I think it is ready for review, and please take a look on the new version.

https://github.com/llvm/llvm-project/pull/114044