[clang] [analyzer] Introduce per-entry-point statistics (PR #131175)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat commented:

Thanks for contributing infrastructural improvements like this; these will be helpful in the analyzer development. Overall I'm satisfied with the idea of this commit; but I marked a few typos and stylistic suggestions in inline comments.

https://github.com/llvm/llvm-project/pull/131175