[clang] [clang][analyzer] Extend lifetime of dynamic extent information (PR #163562)

[Balazs Benics via cfe-commits]

steakhal wrote:

This patch would effectively leak all the extent symbols.
If that would be the objective, we could achieve that by hardcoding that rule in the `SymbolReaper`.

There is also quite some history to the liveness subject around symbol extents on Discourse.
Like https://discourse.llvm.org/t/keeping-the-extent-symbol-alive/76676 and probably more.

I wish you could write up what do we currently have and options to fix this for extents (and possibly for any other symbols for that matter because extents are not alone in this issue).

https://github.com/llvm/llvm-project/pull/163562