[clang] [analyzer] Switch to PostStmt callbacks in ArrayBoundV2 (PR #72107)

[Gábor Horváth via cfe-commits]

Xazax-hun wrote:

I think another question is whether warning on code like `int& val = arr[i]` where `val` is not actually used on the path where `i == size` is OK. I would not block this PR on a case like this, but it might be nice to add a test and potentially a comment about the desired behavior.

https://github.com/llvm/llvm-project/pull/72107