[clang] [clang] Diagnose dangling issues for the "Container<GSLPointer>" case. (PR #107213)

[Haojian Wu via cfe-commits]

hokein wrote:

> Since this is not limited to a hardcoded set of types/stl-containers, this is a substantial change in the behaviour of general Owner<Pointer> types and warrants extra documentation both in GSL analysis docs and ReleaseNotes.

Done. 

https://github.com/llvm/llvm-project/pull/107213